Cisco IOS IP Command Reference, Volume 4 of 4: IP Mobility, Release 12.3 T
IP Mobility Commands: A through I

Table Of Contents

Mobile IP Commands

aaa authorization ipmobile

address (mobile router)

clear ip mobile binding

clear ip mobile host-counters

clear ip mobile router agent

clear ip mobile router registration

clear ip mobile router traffic

clear ip mobile secure

clear ip mobile traffic

clear ip mobile visitor

collocated single-tunnel

description (mobile networks)

home-agent

ip dhcp client mobile renew

ip mobile authentication ignore-spi

ip mobile bindupdate

ip mobile foreign-agent

ip mobile foreign-agent inject-mobile-networks

ip mobile foreign-agent nat traversal

ip mobile foreign-agent skip-aaa-reauthentication

ip mobile foreign-service

ip mobile home-agent

ip mobile home-agent aaa user-password

ip mobile home-agent accounting

ip mobile home-agent nat traversal

ip mobile home-agent redundancy

ip mobile home-agent reject-static-address

ip mobile home-agent resync-sa

ip mobile host

ip mobile mobile-networks

ip mobile prefix-length

ip mobile proxy-host

ip mobile registration-lifetime

ip mobile router

ip mobile router-service

ip mobile router-service collocated

ip mobile router-service collocated registration retry

ip mobile router-service tunnel mode

ip mobile secure aaa-download

ip mobile secure foreign-agent

ip mobile secure home-agent

ip mobile secure host

ip mobile secure mn-aaa

ip mobile secure proxy-host

ip mobile secure visitor

ip mobile tunnel

ip mobile virtual-network

ip mobile vpn-realm


Mobile IP Commands


aaa authorization ipmobile

To authorize Mobile IP to retrieve security associations from the AAA server using TACACS+ or RADIUS, use the aaa authorization ipmobile command in global configuration mode. To remove authorization, use the no form of this command.

aaa authorization ipmobile {[radius | tacacs+] | default} [group server-groupname]

no aaa authorization ipmobile {[radius | tacacs+] | default} [group server-groupname]

Syntax Description

radius

Authorization list named radius.

tacacs+

Authorization list named tacacs+.

default

Default authorization list.

group server-groupname

(Optional) Name of the server group to use.


Defaults

AAA is not used to retrieve security associations for authentication.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.


Usage Guidelines

Mobile IP requires security associations for registration authentication. The security associations are configured on the router or on a AAA server. This command is not needed for the former; but in the latter case, this command authorizes Mobile IP to retrieve the security associations from the AAA server.

Once the authorization list is named, it can be used in other areas such as login. You can only use one named authorization list; multiple named authorization lists are not supported.

The aaa authorization ipmobile default group server-groupname command is the most commonly used method to retrieve security associations from the AAA server.


Note The AAA server does not authenticate the user. It stores the security association that is retrieved by the router to authenticate registration.


Examples

The following example uses TACACS+ to retrieve security associations from the AAA server:

aaa new-model
aaa authorization ipmobile tacacs+
tacacs-server host 1.2.3.4
tacacs-server key mykey
ip mobile host 10.0.0.1 10.0.0.5 virtual-network 10.0.0.0 255.0.0.0 aaa

The following example uses RADIUS as the default group to retrieve security associations from the AAA server:

aaa new-model
aaa authentication login default enable
aaa authorization ipmobile default group radius
aaa session-id common
radius-server host 128.107.162.173 auth-port 1645 acct-port 1646
radius-server retransmit 3
radius-server key cisco
ip mobile host 10.0.0.1 10.0.0.5 virtual-network 10.0.0.0 255.0.0.0 aaa

Related Commands

Command
Description

aaa new-model

Enables the AAA access control model.

ip mobile host

Configures the mobile host or mobile node group.

radius-server host

Specifies a RADIUS server host.

radius-server key

Sets the authentication and encryption key for all RADIUS communications between the router and the RADIUS daemon.

show ip mobile host

Displays mobile node information.

tacacs-server host

Specifies a TACACS host.

tacacs-server key

Sets the authentication encryption key used for all TACACS+ communications between the access server and the TACACS+ daemon.


address (mobile router)

To set the home IP address of the mobile router, use the address command in mobile router configuration mode. To remove the address, use the no form of this command.

address address mask

no address address mask

Syntax Description

address

Home IP address.

mask

Mask for the associated subnet.


Defaults

No default behavior or values.

Command Modes

Mobile router configuration

Command History

Release
Modification

12.2(4)T

This command was introduced.


Usage Guidelines

The address command configures the home IP address and subnet mask of the mobile router. The address and subnet mask identify the home network of the mobile router and are used to discover when the mobile router is at home.

Examples

The following example sets the home IP address and subnet mask of the mobile router:

ip mobile router
 address 10.1.0.1 255.255.0.0

Related Commands

Command
Description

show ip mobile router

Displays configuration information and monitoring information about the mobile router.


clear ip mobile binding

To remove mobility bindings, use the clear ip mobile binding command in privileged EXEC mode.

clear ip mobile binding {all [load standby-group-name] | ip-address | nai string [session-id string]}

Syntax Description

all

Clears all mobility bindings.

load standby-group-name

(Optional) Downloads mobility bindings for a standby group after a clear operation.

ip-address

IP address of a mobile node.

nai string

Network access identifier (NAI) of the mobile node.

session-id string

(Optional) Session identifier. The string value must be fewer than 25 characters in length.


Command Modes

Privileged EXEC

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.1(3)T

The following keywords and argument were added:

all

load

standby-group-name

12.2(2)XC

The nai keyword was added.

12.2(13)T

This command was integrated into Cisco IOS Release 12.2(13)T.

12.3(4)T

The session-id keyword was added.


Usage Guidelines

The home agent creates a mobility binding for each roaming mobile node. Associated with the mobility binding is the tunnel to the visited network and a host route to forward packets destined for the mobile node. Typically, there should be no need to clear the binding because it expires after the lifetime is reached or when the mobile node deregisters.

When the mobility binding is removed through use of this command, the number of users on the tunnel is decremented and the host route is removed from the routing table. The mobile node is not notified.

If the nai string session-id string option is specified, only the binding entry with that session identifier is cleared. If the session-id keyword is not specified, all binding entries (potentially more than one, with different session identifiers) for that NAI are cleared. You can determine the session-id string value by using the show ip mobile binding command.

Use this command with care, because it will disrupt any sessions used by the mobile node. After you use this command, the mobile node will need to reregister to continue roaming.

Examples

The following example administratively stops mobile node 10.2.0.1 from roaming:

Router# show ip mobile binding

Mobility Binding List:
Total 1
10.2.0.1: 
    Care-of Addr 68.0.0.31, Src Addr 68.0.0.31, 
    Lifetime granted 02:46:40 (10000), remaining 02:46:32
    Flags SbdmGvt, Identification B750FAC4.C28F56A8, 
    Tunnel100 src 66.0.0.5 dest 68.0.0.31 reverse-allowed
    Routing Options - (G)GRE

Router# clear ip mobile binding 10.2.0.1

Router# show ip mobile binding

Related Commands

Command
Description

show ip mobile binding

Displays the mobility binding table.


clear ip mobile host-counters

To clear the mobility counters specific to each mobile node, use the clear ip mobile host-counters command in EXEC mode.

clear ip mobile host-counters [[ip-address | nai string] undo]]

Syntax Description

ip-address

(Optional) IP address of a mobile node.

nai string

(Optional) Network access identifier of the mobile node.

undo

(Optional) Restores the previously cleared counters.


Command Modes

EXEC

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2(2)XC

The nai keyword was added.

12.2(13)T

This command was integrated into Cisco IOS Release 12.2(13)T.


Usage Guidelines

This command clears the counters that are displayed when you use the show ip mobile host command. The undo keyword restores the counters (this option is useful for debugging).

Examples

The following example shows how the counters can be used for debugging:

Router# show ip mobile host

10.0.0.1:
    Allowed lifetime 10:00:00 (36000/default)
    Roaming status -registered-, Home link on virtual network 20.0.0.0/8
    Accepted 2, Last time 04/13/02 19:04:28
    Overall service time 00:04:42
    Denied 0, Last time -never-
    Last code `-never- (0)'
    Total violations 1
    Tunnel to MN - pkts 0, bytes 0
    Reverse tunnel from MN - pkts 0, bytes 0

    .
Router# clear ip mobile host-counters

Router# show ip mobile host-counters

20.0.0.1:
    Allowed lifetime 10:00:00 (36000/default)
    Roaming status -Unregistered-, Home link on virtual network 20.0.0.0/8
    Accepted 0, Last time -never-
    Overall service time -never-
    Denied 0, Last time -never-
    Last code `-never- (0)'
    Total violations 0
    Tunnel to MN - pkts 0, bytes 0
    Reverse tunnel from MN - pkts 0, bytes 0

Related Commands

Command
Description

show ip mobile host

Displays mobile node counters and information.


clear ip mobile router agent

To delete learned agents and the corresponding care-of address of the foreign agent from the mobile router agent table, use the clear ip mobile router agent command in privileged EXEC mode.

clear ip mobile router agent [ip-address]

Syntax Description

ip-address

(Optional) IP address of an agent. If not specified, all agents are deleted from the agent table.


Defaults

No default behavior or values.

Command Modes

Privileged EXEC

Command History

Release
Modification

12.2(4)T

This command was introduced.


Usage Guidelines

The mobile router maintains an agent table listing active agents and the corresponding care-of address of the foreign agent. The mobile router uses this agent table to decide which foreign agent to register with. The mobile router updates the table when it receives advertisements. If an advertisement expires, its entry is automatically deleted from the table.

The clear ip mobile router agent ip-address option allows you to remove a specific agent.

Examples

The following example removes all agents from the mobile router agent table:

Router# clear ip mobile router agent

Related Commands

Command
Description

show ip mobile router interface

Displays information about the agents for the mobile router.


clear ip mobile router registration

To delete registration entries from the mobile router registration table, use the clear ip mobile router registration command in privileged EXEC mode.

clear ip mobile router registration [ip-address]

Syntax Description

ip-address

(Optional) IP address of a specific agent. If not specified, all registration entries are deleted.


Defaults

No default behavior or values.

Command Modes

Privileged EXEC

Command History

Release
Modification

12.2(4)T

This command was introduced.


Usage Guidelines

The mobile router maintains a registration table listing registration entries that are used for retransmissions. For example, a registration request is sent when no reply is received or the lifetime is about to expire.

A registration request can be removed from the table to prevent further registration requests from being sent to the agent. The clear ip mobile router registration ip-address option allows you to remove a registration to a specific agent.

Clearing an active registration will cause the mobile router to attempt to deregister.

Examples

The following example removes all registration entries from the mobile router registration table:

Router# clear ip mobile router registration

Related Commands

Command
Description

show ip mobile router registration

Displays the pending and accepted registrations of the mobile router.


clear ip mobile router traffic

To clear the counters that the mobile router maintains, use the clear ip mobile router traffic command in privileged EXEC mode.

clear ip mobile router traffic

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values.

Command Modes

Privileged EXEC

Command History

Release
Modification

12.2(4)T

This command was introduced.


Usage Guidelines

Mobile router counters are accumulated during operation. They are useful for debugging and monitoring.

Examples

The following example shows how the mobile router counters can be used for debugging:

Router# show ip mobile router traffic

Mobile Router Counters:

Agent Discovery:
  Solicitations sent 90, advertisements received 17
  Agent reboots detected 0
Registrations:
  Register 70, Deregister 0 requests sent
  Register 70, Deregister 0 replies received
  Requests accepted 68, denied 1 by HA 1 /FA 0
  Denied due to mismatched ID 1
  .
  .
  .
Router# clear ip mobile router traffic

Router# show ip mobile router traffic

Mobile Router Counters:

Agent Discovery:
  Solicitations sent 0, advertisements received 0
  Agent reboots detected 0
Registrations:
  Register 0, Deregister 0 requests sent
  Register 0, Deregister 0 replies received
  Requests accepted 0, denied 0 by HA 0 /FA 0
  Denied due to mismatched ID 0
  .
  .
  .

Related Commands

Command
Description

show ip mobile router traffic

Displays the counters that the mobile router maintains.


clear ip mobile secure

To clear and retrieve remote security associations, use the clear ip mobile secure command in EXEC mode.

clear ip mobile secure {host lower [upper] | nai string | empty | all} [load]

Syntax Description

host

Mobile node host.

lower

IP address of mobile node. Can be used alone, or as lower end of a range of IP addresses.

upper

(Optional) Upper end of a range of IP addresses.

nai string

Network access identifier of the mobile node.

empty

Load in only mobile nodes without security associations. Must be used with the load keyword.

all

Clears all mobile nodes.

load

(Optional) Reload the security association from the AAA server after security association has been cleared.


Command Modes

EXEC

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2(2)XC

The nai keyword was added.

12.2(13)T

This command was integrated into Cisco IOS Release 12.2(13)T.


Usage Guidelines

Security associations are required for registration authentication. They can be stored on an AAA server. During registration, they may be stored locally after retrieval from the AAA server. The security association on the router may become stale or out of date when the security association on the AAA server changes.

This command clears security associations that have been downloaded from the AAA server.


Note Security associations that are manually configured on the router or not stored on the router after retrieval from the AAA server are not applicable.


Examples

In the following example, the AAA server has the security association for user 10.2.0.1 after registration:

Router# show ip mobile secure host 10.2.0.1

Security Associations (algorithm,mode,replay protection,key):
10.2.0.1:
    SPI 300,  MD5, Prefix-suffix, Timestamp +/- 7,
    Key `oldkey' 1230552d39b7c1751f86bae5205ec0c8

If you change the security association stored on the AAA server for this mobile node, the router clears the security association and reloads it from the AAA server:

Router# clear ip mobile secure host 10.2.0.1 load

Router# show ip mobile secure host 10.2.0.1

10.2.0.1:
    SPI 300,  MD5, Prefix-suffix, Timestamp +/- 7,
    Key `newkey' 1230552d39b7c1751f86bae5205ec0c8

Related Commands

Command
Description

ip mobile secure

Specifies the mobility security associations for mobile host, visitor, home agent, and foreign agent.


clear ip mobile traffic

To clear counters, use the clear ip mobile traffic command in EXEC mode.

clear ip mobile traffic [undo]

Syntax Description

undo

(Optional) Restores the previously cleared counters.


Command Modes

EXEC

Command History

Release
Modification

12.0(1)T

This command was introduced.


Usage Guidelines

Mobile IP counters are accumulated during operation. They are useful for debugging and monitoring.

This command clears all Mobile IP counters. The undo keyword restores the counters (which is useful for debugging). See the show ip mobile traffic command for a description of all counters.

Examples

The following example shows how counters can be used for debugging:

Router# show ip mobile traffic
IP Mobility traffic:
Advertisements:
    Solicitations received 0
    Advertisements sent 0, response to solicitation 0
Home Agent Registrations:
    Register 8, Deregister 0 requests
    Register 7, Deregister 0 replied
    Accepted 6, No simultaneous bindings 0
    Denied 1, Ignored 1 
    Unspecified 0, Unknown HA 0
    Administrative prohibited 0, No resource 0
    Authentication failed MN 0, FA 0
    Bad identification 1, Bad request form 0
    .
Router# clear ip mobile traffic

Router# show ip mobile traffic
IP Mobility traffic:
Advertisements:
    Solicitations received 0
    Advertisements sent 0, response to solicitation 0
Home Agent Registrations:
    Register 0, Deregister 0 requests
    Register 0, Deregister 0 replied
    Accepted 0, No simultaneous bindings 0
    Denied 0, Ignored 0 
    Unspecified 0, Unknown HA 0
    Administrative prohibited 0, No resource 0
    Authentication failed MN 0, FA 0
    Bad identification 0, Bad request form 0

Related Commands

Command
Description

show ip mobile traffic

Displays protocol counters.


clear ip mobile visitor

To remove visitor information, use the clear ip mobile visitor command in privileged EXEC mode.

clear ip mobile visitor [ip-address | nai string [session-id string] [ip-address]]

Syntax Description

ip-address

(Optional) IP address. If not specified, visitor information will be removed for all addresses.

nai string

(Optional) Network access identifier (NAI) of the mobile node.

session-id string

(Optional) Session identifier. The string value must be fewer than 25 characters in length.

ip-address

(Optional) IP address associated with the NAI.


Command Modes

EXEC

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2(2)XC

The nai keyword and associated variables were added.

12.2(13)T

This command was integrated into Cisco IOS Release 12.2(13)T.

12.3(4)T

The session-id keyword was added.


Usage Guidelines

The foreign agent creates a visitor entry for each accepted visitor. The visitor entry allows the mobile node to receive packets while in a visited network. Associated with the visitor entry is the Address Resolution Protocol (ARP) entry for the visitor. There should be no need to clear the entry because it expires after lifetime is reached or when the mobile node deregisters.

When a visitor entry is removed, the number of users on the tunnel is decremented and the ARP entry is removed from the ARP cache. The visitor is not notified.

If the nai string session-id string option is specified, only the visitor entry with that session identifier is cleared. If the session-id keyword is not specified, all visitor entries (potentially more than one, with different session identifiers) for that NAI are cleared. You can determine the session-id string value by using the show ip mobile visitor command.

Use this command with care because it may terminate any sessions used by the mobile node. After you use this command, the visitor will need to reregister to continue roaming.

Examples

The following example administratively stops visitor 172.21.58.16 from visiting:

Router# clear ip mobile visitor 172.21.58.16

Related Commands

Command
Description

show ip mobile visitor

Displays the table containing the visitor list of the foreign agent.


collocated single-tunnel

To configure the number of tunnels between the mobile router and home agent when registering with a collocated care-of address (CCoA), use the collocated single-tunnel command in mobile router configuration mode.

collocated single-tunnel

Syntax Description

This command has no arguments or keywords.

Defaults

Defaults to single-tunnel enabled.

Command Modes

Mobile router

Command History

Release
Modification

12.2(15)T

This command was introduced.


Usage Guidelines

This command is used as a "placeholder" only and defaults to single-tunnel enabled. This command can not be unconfigured. In future Cisco IOS releases, a dual-tunnel capability will be needed for IPSec between the mobile router and the home agent. At that time, this command will be optional with dual tunnels (no collocated single-tunnel) being the default. This command is provided now for backward compatibility when the dual-tunnel capablity is implemented.

description (mobile networks)

To add a description to a mobile router configuration, use the description command in mobile networks configuration mode. To remove the description, use the no form of this command.

description string

no description

Syntax Description

string

Comment or description about the mobile router or its networks.


Defaults

No default behavior or values.

Command Modes

Mobile networks configuration

Command History

Release
Modification

12.2(4)T

This command was introduced.


Usage Guidelines

The description command is meant solely as a comment to be put in the configuration to help you remember information about the configured mobile router or its mobile networks.

Examples

The following example shows how to add a description for the mobile router:

ip mobile mobile-networks 10.2.0.1
 description mobileunit
 network 172.6.1.0 255.255.255.0
 network 172.6.2.0 255.255.255.0

Related Commands

Command
Description

show ip mobile mobile-networks

Displays a list of mobile networks associated with the mobile router.


home-agent

To specify the home agent that the mobile router uses during registration, use the home-agent command in mobile router configuration mode. To disable the home agent, use the no form of this command.

home-agent ip-address [priority level]

no home-agent ip-address [priority level]

Syntax Description

ip-address

Home IP address.

priority level

(Optional) Priority level that prioritizes which home agent address is the best to use during registration. The range is from 0 to 255, where 0 denotes the lowest priority and 255 denotes the highest priority. The default is 100.


Defaults

The default priority level is 100.

Command Modes

Mobile router configuration

Command History

Release
Modification

12.2(4)T

This command was introduced.


Usage Guidelines

The home-agent command specifies which home agent the mobile router uses for registration and to detect when it is home. The priority level determines which home agent address to register with, although all addresses are on the same home agent. The mobile router registers with the home agent with the highest priority level.

The home agent address list is used to detect when the mobile router is home. The mobile router knows that it is at home when the source of the agent advertisements is an IP source address that exists on the home agent address list.

Examples

The following example shows that the mobile router will use the home agent address 1.1.1.1 during registration and will detect when it is at home after receiving agent advertisements from either address 1.1.1.1 or 2.2.2.2:

router mobile
ip mobile router
  address 10.1.0.1 255.255.0.0
  home-agent 1.1.1.1 priority 101
  home-agent 2.2.2.2 priority 100

Related Commands

Command
Description

show ip mobile router

Displays configuration information and monitoring statistics about the mobile router.


ip dhcp client mobile renew

To configure the number of renewal attempts and the interval between attempts for renewing the current IP address acquired by DHCP, use the ip dhcp client mobile renew command in interface configuration mode. To disable this functionality, use the no form of this command.

ip dhcp client mobile renew count number interval msec

no ip dhcp client mobile renew count number interval msec

Syntax Description

count number

Number of renewal attempts to renew the current IP address before starting the DHCP discovery process. The range is from 0 to 10 attempts. The default is 2 attempts.

interval msec

Interval to wait between renewal attempts. The range is from 1 to 1000 msec. The default is 50 msec.


Defaults

count number: 2
interval msec: 50

Command Modes

Interface configuration

Command History

Release
Modification

12.3(14)T

This command was introduced.


Usage Guidelines

Mobile DHCP clients automatically attempt to renew an existing IP address in response to certain events, such as moving between wireless access points. The number of renewal attempts, and the interval between those attempts, depending on network conditions, can be modified by using the ip dhcp client mobile renew command.

Examples

In the following example, the DHCP client will make four attempts to renew its current IP address with an interval of 30 milliseconds between attempts :

interface FastEthernet0
 ip dhcp client mobile renew count 4 interval 30

Related Commands

Command
Description

ip address dhcp

Acquires an IP address on an interface from DHCP.


ip mobile authentication ignore-spi

To enable the home agent or foreign agent to accept RFC-2002 based mobile nodes or foreign agents that don't include the security parameter index (SPI) in the authentication extension of the registration message, use the ip mobile authentication ignore-spi command in global configuration mode. To disable this functionality, use the no form of this command.

ip mobile authentication ignore-spi

no ip mobile authentication ignore-spi

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values.

Command Modes

Global configuration.

Command History

Release
Modification

12.2(8)BY

This command was introduced.

12.3(4)T

This command was integrated into Cisco IOS Release 12.3(4)T.


Usage Guidelines

Cisco IOS software supports the Mobile-Home Authentication Extension (MHAE). All registration messages between a mobile and a home agent include a mandatory authentication extension.

In RFC 2002, the SPI field was not included to calculate the authenticator value in the authentication extension of the registration message. In RFC 3220 and 3344, the SPI field in the authentication extension is used as part of the data over which the authentication algorithm must be computed.

The command turns off authentication and allows an RFC-2002 based mobile node and foreign agent to register with the home agent even though the SPI field is not included in the authentication extension of the registration message. The foreign agent will accept both RFC 2002 and RFC 3220/3344 based visitors and the home agent will accept both RFC 2002 and RFC 3220/3344 based mobile nodes and foreign agents.

Examples

The following example allows the home agent to accept registration messages without the SPI in the authentication extension:

ip mobile authentication ignore-spi

ip mobile bindupdate

To enable a home agent to send a binding update message to a foreign agent, use the ip mobile bindupdate command in global configuration mode. To disable this functionality, use the no form of this command.

ip mobile bindupdate [acknowledge] [maximum seconds] [minimum seconds] [retry number]

no ip mobile bindupdate [acknowledge] [maximum seconds] [minimum seconds] [retry number]

Syntax Description

acknowledge

(Optional). Indicates that the foreign agent must acknowledge receipt of a binding update message.

maximum seconds

(Optional) Maximum period (in seconds) that the home agent waits before retransmission of a binding update message. The default is 10 seconds.

minimum seconds

(Optional) Minimum period (in seconds) that the home agent waits before retransmission of a binding update message. The default is 1 second.

retry number

(Optional) Number of times to retry sending the binding update message. Retransmission stops after the maximum number of retries are attempted. The range is from 1 to 4; the default retry is 4.


Defaults

maximum seconds: 10 seconds
minimum seconds: 1 second
retry number: 4 retries

Command Modes

Global configuration

Command History

Release
Modification

12.2(8)BY

This command was introduced.

12.3(4)T

This command was integrated into Cisco IOS Release 12.3(4)T.


Usage Guidelines

This command enables the home agent to send a binding update message to the previous foreign agent when the mobile node moves to a new care-of address. The binding update message informs the foreign agent that a mobile node has moved and it can reclaim resources associated with that mobile node such as a visitor entry or visitor route.

Typically, resources on the foreign agent are not reclaimed until the mobility binding lifetime expires for that mobile node. By using this command, the foreign agent does not have to wait to reclaim resources used by the mobile node when that mobile node is no longer associated with the foreign agent.

Without this command configured, when a mobile node moves from foreign agent 1 to foreign agent 2 or when the home agent removes the binding, foreign agent 1 does not know that the mobile node has moved and the resources on foreign agent 1 associated with the mobile node will not be cleared until the lifetime expires for the mobile node.

If the acknowledge keyword is specified, the home agent periodically retransmits a binding update message until it receives a binding acknowledgement from the foreign agent or until the number of retries is exceeded.

The home agent and foreign agent must share a security association. The binding update message from the home agent and the binding update acknowledgement from the foreign agent must contain a FHAE (Foreign-Home Authentication Extension). If the FHAE is not configured on the home agent with the ip mobile secure command, the home agent will not send a binding update message even if the ip mobile bindupdate command is configured.

Examples

The following example configures the home agent to wait a maximum of 8 seconds before retransmitting a binding update message to a foreign agent. The foreign agent must send an acknowledgement of this binding update message upon receipt.

ip mobile bindupdate acknowledge maximum 8 retry 3 
ip mobile secure foreign-agent 10.31.1.1 spi 100 key hex 23456781234567812345678123456781

The following example configures the security association on the foreign agent. Without the security association configured on the home agent and the foreign agent, the binding update message would not be sent or processed.

ip mobile secure home-agent 172.31.10.1 spi 100 key hex 23456781234567812345678123456781

ip mobile foreign-agent

To enable foreign agent service, use the ip mobile foreign-agent command in global configuration mode. To disable this service, use the no form of this command.

ip mobile foreign-agent [care-of interface [interface-only] [transmit-only] | reg-wait seconds | local-timezone reverse-tunnel private-address]

no ip mobile foreign-agent [care-of interface [interface-only] [transmit-only] | reg-wait seconds | local-timezone reverse-tunnel private-address]

Syntax Description

care-of interface

IP address of the interface. Sets the care-of address on the foreign agent. Multiple care-of addresses can be configured. At least one care-of address must be configured for foreign agent service.

interface-only

(Optional) Enables the specified interface to advertise only its own address as the care-of address. Other interfaces configured for foreign agent service will not advertise this care-of address.

transmit-only

(Optional) Informs Mobile IP that the interface is being used on a unidirectional link and will transmit only. This interface will be used as the source interface for this care-of address for any registration request received on another interface.

reg-wait seconds

(Optional) Pending registration expires after the specified number of seconds if no reply is received. Range is from 5 to 600 seconds. Default is 15.

local-timezone

(Optional) Uses the local time zone to generate identification fields.

reverse-tunnel private-address

(Optional) Forces a mobile node with a private address to register with reverse tunneling.


Defaults

reg-wait seconds: 15

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2(13)T

The interface-only, transmit-only, and reverse-tunnel private-address keywords were added.

12.2(3)XC

The local-timezone keyword was added.

12.3(4)T

This command was integrated into Cisco IOS Release 12.3(4)T.


Usage Guidelines

This command enables foreign agent service when at least one care-of address is configured. When no care-of address exists, foreign agent service is disabled.

The foreign agent is responsible for relaying the registration request to the home agent, setting up a tunnel to the home agent, and forwarding packets to the mobile node. The show commands used to display relevant information are shown in parentheses in the following paragraph.

When a registration request comes in, the foreign agent will ignore requests when foreign agent service is not enabled on an interface or when no care-of address is advertised. If a security association exists for a visiting mobile node, the visitor is authenticated. The registration bitflag is handled as described in Table 1. The foreign agent checks the validity of the request. If successful, the foreign agent relays the request to the home agent, appending an FH authentication extension if a security association for the home agent exists. The pending registration timer of 15 seconds is started (show ip mobile visitor pending command). At most, five outstanding pending requests per mobile node are allowed. If a validity check fails, the foreign agent sends a reply with error code to the mobile node (reply codes are listed in Table 2). A security violation is logged when visiting mobile node authentication fails (show ip mobile violation command).

When a registration reply comes in, the home agent is authenticated (show ip mobile secure home-agent command) if a security association exists for the home agent (IP source address or home agent address in reply). The reply is relayed to the mobile node.

When registration is accepted, the foreign agent creates or updates the visitor table, which contains the expiration timer. If no binding existed before this registration, a virtual tunnel is created, a host route to the mobile node via the interface (of the incoming request) is added to the routing table (show ip route mobile command), and an ARP entry is added to avoid the sendingof ARP requests for the visiting mobile node. Visitor binding is removed (along with its associated host route, tunnel, and ARP entry) when the registration lifetime expires or deregistration is accepted.

When registration is denied, the foreign agent will remove the request from the pending registration table. The table and timers of the visitor will be unaffected.

When a packet destined for the mobile node arrives on the foreign agent, the foreign agent deencapsulates the packet and forwards it out its interface to the visiting mobile node, without sending ARP requests.

The care-of address must be advertised by the foreign agent. This adddress is used by the mobile node to register with the home agent. The foreign agent and home agent use this address as the source and destination point of tunnel, respectively. The foreign agent is not enabled until at least one care-of address is available. The foreign agent will advertise on interfaces configured with the ip mobile foreign-service command.

Only care-of addresses with interfaces that are up are considered available.

The interface-only and transmit-only keywords are used in an aysmmetric link environment, such as satellite communications, where separate uplinks and downlinks exist. The ip mobile foreign-agent care-of interface interface-only command enables the specified interface to advertise only its own address as the care-of address. All other care-of addresses are not advertised. Other foreign agent interfaces configured for foreign-service will not advertise interface-only care-of addresses. The ip mobile foreign-agent care-of interface transmit-only command informs Mobile IP that the interface acts as an uplink. Registration requests and replies received for this care-of address are treated as transmit-only. This interface will not hear any solicitations.

Use the reverse-tunnel private-address keywords to force a mobile node with a private address to register with reverse tunnel. Private addresses are IP addresses in the following ranges:

10.0.0.0 to 10.255.255.255 (10/8 prefix)

172.16.0.0 to 172.31.255.255 (172.16/12 prefix)

192.168.0.0 to 192.168.255.255 (192.168/16 prefix)

Table 1 lists mobile node registration request service bitflags.

Table 1 Mobile Node Registration Request Service Bitflags

Bit Set
Registration Request

S

No operation. Not applicable to foreign agent.

B

No operation. Not applicable to foreign agent.

D

Make sure source IP address belongs to the network of the interface.

M

Deny request. Minimum IP encapsulation is not supported.

G

No operation. GRE encapsulation is supported.

r

Sent as zero; ignored on reception. Do not allocate for any other uses.

V

Reserved.

T

Deny if reverse tunneling is disabled on the foreign agent.

reserved

Deny request. Reserved bit must not be set.


Table 2 lists foreign agent reply codes.

Table 2 Foreign Agent Reply Codes 

Code
Reason

64

Reason unspecified.

65

Administratively prohibited.

66

Insufficient resource.

67

Mobile node failed authentication.

68

Home agent failed authentication.

69

Requested lifetime is too long.

70

Poorly formed request.

71

Poorly formed reply.

72

Requested encapsulation is unavailable.

74

Reverse tunnel unsupported.

75

Reverse tunnel is mandatory and T bit is not set.

76

Mobile node too distant.

77

Invalid care-of address.

78

Registration timeout.

79

Delivery style not supported.

80

Home network unreachable (ICMP error received).

81

Home agent host unreachable (ICMP error received).

82

Home agent port unreachable (ICMP error received).

88

Home agent unreachable (other ICMP error received).

98

Missing home agent.

99

Missing home agent address.

100

Unsupported vendor ID or unable to interpret vendor extension type in the registration request extensions sent by the mobile node to the foreign agent.

101

Unsupported vendor ID or unable to interpret vendor extension type in the registration request extensions sent by the home agent to the foreign agent.

104

Unknown challenge.

105

Missing challenge.

106

Stale challenge.


Examples

The following example enables foreign agent service on Ethernet interface 1, advertising 10.0.0.1 as the care-of address:

ip mobile foreign-agent care-of Ethernet0
interface Ethernet0
 ip address 10.0.0.1 255.0.0.0
interface Ethernet1
 ip mobile foreign-service

The following example enables foreign agent service on serial interface 4, advertising 10.0.0.2 as the only care-of address. The uplink interface is configured as a transmit-only interface.

ip mobile foreign-agent care-of Serial4 interface-only transmit-only
interface Serial4
! Uplink interface
 ip address 10.0.0.2 255.255.255.0
 ip irdp
!
 ip mobile foreign-service
!

Related Commands

Command
Description

debug ip mobile advertise

Displays advertisement information.

ip mobile foreign-service

Enables foreign agent service on an interface if care-of addresses are configured.

show ip mobile globals

Displays global information for mobile agents.

show ip mobile interface

Displays advertisement information for interfaces that are providing foreign agent service or are home links for mobile nodes.

show ip mobile secure

Displays mobility security associations for mobile host, mobile visitor, foreign agent, or home agent.

show ip mobile violation

Displays information about security violations.

show ip mobile visitor

Displays the table containing the visitor list of the foreign agent.

show ip route mobile

Displays the current state of the routing table for mobile routes.


ip mobile foreign-agent inject-mobile-networks

To enable direct routing to mobile networks via the foreign agent, use the ip mobile foreign-agent inject-mobile-networks command in global configuration mode. To disable this functionality, use the no form of this command.

ip mobile foreign-agent inject-mobile-networks [mobnetacl access-list-identifier]

no ip mobile foreign-agent inject-mobile-networks [mobnetacl access-list-identifier]

Syntax Description

mobnetacl

(Optional) Specifies that the foreign agent can provide direct routing for only the mobile networks covered by the specified access list.

access-list-identifier

(Optional) Name of an access list defined using the ip access-list command or number of an access list defined using the access-list command.


Defaults

Direct routing via the foreign agent is disabled.

Command Modes

Global configuration

Command History

Release
Modification

12.3(7)T

This command was introduced.


Usage Guidelines

Configure the ip mobile foreign-agent inject-mobile-networks command on the foreign agent to enable direct routing.

The value entered for the access-list-identifier argument must match the name of an access list defined using the ip access-list command or the number of an access list defined using the access-list command.

Examples

The following example configures the access list named mobile-net-list and enables direct routing via the foreign agent for mobile networks specified on that access list.

ip access-list standard mobile-net-list
 permit any
!
ip mobile foreign-agent inject-mobile-networks mobnetacl mobile-net-list

Related Commands

Command
Description

access-list (IP standard)

Defines a standard IP access list.

ip access-list

Defines an IP access list by name.

show ip mobile globals

Displays global information for mobile agents.


ip mobile foreign-agent nat traversal

To enable NAT traversal support for mobile IP (MIP) foreign agents (FAs), use the ip mobile foreign-agent nat traversal command in global configuration mode. To disable NAT traversal support, use the no form of this command.

ip mobile foreign-agent nat traversal [keepalive keepalive-time] [force]

no ip mobile foreign-agent nat traversal [keepalive keepalive-time] [force]

Syntax Description

keepalive keepalive-time

(Optional) Allows the FA to use a configured time for keepalive messages when the home agent (HA) keepalive time was not configured. The range is 10 to 600 seconds. Default is 110 seconds.

Note The Cisco HA will never send a time of zero. If you have Cisco hardware only, you do not need to configure the keepalive keyword.

force

(Optional) Allows the FA to force the HA to allocate a User Datagram Protocol (UDP) tunnel. The force keyword only sets the "force" bit in the message extension. The default is not to force UDP tunneling.


Defaults

Network Address Translation (NAT) traversal support for FAs is disabled.

Command Modes

Global configuration

Command History

Release
Modification

12.3(8)T

This command was introduced.


Usage Guidelines

You need to enable this command under the following circumstances:

If you have a NAT box in your network.

If you have a NAT box in your network, and you are using private an IP address for the care-of address (CoA) or source IP address in the registration request.

A likely scenario for using this command and when to set the force bit is when there is a firewall between a FA and HA. The firewall blocks IP-in-IP and GRE packets but permits UDP packets.

Examples

The following example shows a FA configuration with a keepalive time of 45 and forced UDP tunneling.

ip mobile foreign-agent care-of Ethernet2/2
ip mobile foreign-agent nat traversal keepalive 45 force

Related Commands

Command
Description

debug ip mobile

Displays IP mobility activities.

ip mobile home-agent nat traversal

Enables NAT UDP traversal support for MIP HAs.

show ip mobile bindings

Displays the mobility binding table.

show ip mobile globals

Displays global information about MIP HAs, FAs, and MNs.

show ip mobile visitor

Displays information about UDP tunneling.

show ip mobile tunnel

Displays the table that contains a visitor list of FAs.


ip mobile foreign-agent skip-aaa-reauthentication

To enable FA-CHAP during Mobile IP registration, and then to skip it in all subsequent re-registrations, use the ip mobile foreign-agent skip-aaa-reauthentication command in global configuration mode. To disable this feature, use the no form of this command.

ip mobile foreign-agent skip-aaa-reauthentication

no ip mobile foreign-agent skip-aaa-reauthentication

Syntax Description

There are no keywords or arguments for this commmand.

Defaults

Disabled

Command Modes

Global configuration

Command History

Release
Modification

12.3(11)T

This command was introduced.


Usage Guidelines

FA-CHAP is a mechanism for authentication in Mobile IP. As per IS835, FA-CHAP is mandatory during Mobile IP call setup (registration), and requires access to a AAA server. A Mobile IP call has a parameter lifetime, so in order to continue a Mobile IP call, re-registration is required before the lifetime expires, and this re-registration leads to extending of lifetime.

Because FA-CHAP is mandatory, and the call is authenticated during registration, it may be undesirable to access AAA during re-registration of the Mobile IP call. The ip mobile foreign-agent skip-aaa-reauthentication command provides flexibility in this scenario.

When this command is configured, FA-CHAP is performed during Mobile IP registration, and is skipped in all subsequent re-registrations.

The default value is "false", implying that AAA access is not skipped during Mobile IP re-registration.

Examples

The following example shows that FA-CHAP is enabled during Mobile IP registration, but disabled for all subsequent re-registrations:

ip mobile foreign-agent skip-aaa-reauthentication

ip mobile foreign-service

To enable foreign agent service if care-of addresses are configured, use the ip mobile foreign-service command in interface configuration mode. To disable this service, use the no form of this command.

ip mobile foreign-service [home-access access-list] [limit number] [registration-required] [challenge {timeout value | window number | forward-mfce}] [reverse-tunnel [mandatory]]

no ip mobile foreign-service [home-access access-list] [limit number] [registration-required] [challenge {timeout value | window number | forward-mfce}] [reverse-tunnel [mandatory]]

Syntax Description

home-access access-list

(Optional) Controls which home agent addresses mobile nodes can be used to register. The access list can be a string or number from 1 to 99. For releases prior to 12.3T, you cannot use this keyword when you enable foreign agent service on a subinterface.

limit number

(Optional) Number of visitors allowed on the interface. The Busy (B) bit will be advertised when the number of registered visitors reaches this limit. For releases prior to 12.3T, you cannot use this keyword when you enable foreign agent service on a subinterface.

registration-required

(Optional) Solicits registration from the mobile node even if it uses colocated care-of addresses. The Registration-required (R) bit will be advertised. For releases prior to 12.3T, you cannot use this keyword when you enable foreign agent service on a subinterface.

challenge

(Optional) Configures the foreign agent challenge parameters. For releases prior to 12.3T, you cannot use this keyword when you enable foreign agent service on a subinterface.

timeout value

(Optional) Challenge timeout in seconds. Possible values are from 1 to 10.

window number

(Optional) Maximum number of valid challenge values to maintain. Possible values are from 1 to 10. The default is 2.

forward-mfce

(Optional) Enables the foreign agent to forward mobile foreign challenge extensions (MFCEs) and mobile node-AAA extensions to the home agent.

reverse-tunnel [mandatory]

(Optional) Enables reverse tunneling on the foreign agent. For releases prior to 12.3T, you cannot use this keyword when you enable foreign agent service on a subinterface.


Defaults

Foreign agent service is not enabled.
There is no limit to the number of visitors allowed on an interface.
window number: 2
Foreign agent reverse tunneling is not enabled. When foreign agent reverse tunneling is enabled, it is not mandatory by default.

Command Modes

Interface configuration and global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.1(3)XS

The challenge keyword and associated parameters were added.

12.2(2)XC

The reverse-tunnel [mandatory] keywords were added.

12.2(13)T

The challenge keyword and associated parameters and the reverse-tunnel [mandatory] keywords were integrated into Cisco IOS Release 12.2(13)T.

12.3(11)T

Global configuration mode was added.


Usage Guidelines

This command enables foreign agent service on the interface or all interfaces (in global configuration mode). The foreign agent (F) bit will be set in the agent advertisement, which is appended to the IRDP router advertisement whenever the foreign agent or home agent service is enabled on the interface.


Note The Registration-required bit only tells the visiting mobile node to register even if the visiting mobile node is using a colocated care-of address. You must set up packet filters to enforce this. For example, you could deny packets destined for port 434 from the interface of this foreign agent.


When you use the reverse-tunnel keyword to enable foreign agent reverse tunneling on an interface, the reverse tunneling support (T) bit is set in the agent advertisement.

Cisco Express Forwarding (CEF) switching is currently not supported on a foreign agent when reverse tunneling is enabled. If reverse tunneling is enabled at the foreign agent, disable CEF on the foreign agent, using the no ip cef global configuration command. If the foreign agent does not support reverse tunneling, then there is no need to disable CEF at the global configuration level.

Table 3 lists the advertised bitflags.

Table 3 Foreign Agent Advertisement Bitflags 

Bit Set
Service Advertisement

T

Set if the reverse-tunnel parameter is enabled.

R

Set if the registration-required parameter is enabled.

B

Set if the number of visitors reached the limit parameter.

H

Set if the interface is the home link to the mobile host (group).

F

Set if foreign-agent service is enabled.

M

Never set.

G

Always set.

V

Reserved.

reserved

Never set.


Examples

The following example shows how to enable foreign agent service for up to 100 visitors:

interface Ethernet 0
 ip mobile foreign-service limit 100 registration-required

The following example shows how to enable foreign agent reverse tunneling:

interface ethernet 0
 ip mobile foreign-service reverse-tunnel

The following example shows how to configure foreign agent challenge parameters:

interface ethernet 0
 ip mobile foreign-service challenge window 2

Related Commands

Command
Description

ip cef

Enables CEF on the RP card.

ip mobile tunnel

Specifies the settings of tunnels created by Mobile IP.

show ip mobile interface

Displays advertisement information for interfaces that are providing foreign agent service or are home links for mobile nodes.


ip mobile home-agent

To enable and control home agent (HA) services, use the ip mobile home-agent command in global configuration mode. To disable these services, use the no form of this command.

ip mobile home-agent [address ip-address] [broadcast] [care-of-access access-list] [lifetime seconds] [nat-detect] [replay seconds] [reverse-tunnel-off] [roam-access access-list] [strip-nai-realm] [suppress-unreachable] [local-timezone] [unknown-ha [accept [reply] | deny]] [send-mn-address]

no ip mobile home-agent [address ip-address] [broadcast] [care-of-access access-list] [lifetime seconds] [nat-detect] [replay seconds] [reverse-tunnel-off] [roam-access access-list] [strip-nai-realm] [suppress-unreachable] [local-timezone] [unknown-ha [accept [reply] | deny]] [send-mn-address]

Syntax Description

address ip-address

(Optional) Specifies the IP address of the HA.

Note This option is only applicable when HA redundancy is used for virtual networks.

broadcast

(Optional) Enables forwarding of broadcast datagrams to the mobile node (MN). By default, broadcasting is disabled.

care-of-access access-list

(Optional) Controls which care-of addresses (CoAs) in registration requests are permitted by the HA. By default, all CoAs are permitted. The access-list argument can be a string or number from 1 to 99.

lifetime seconds

(Optional) Specifies the global registration lifetime for an MN in seconds. Range is from 3 to 65535 (infinity). Default is 36000 (10 hours).

Note This configuration can be overridden by the individual MN configuration. Registrations requesting a lifetime greater than this value will still be accepted, but will use this lifetime value.

nat-detect

(Optional) Allows the HA to detect registration requests from a MN traversing a Network Address Translation (NAT)-enabled device and apply a tunnel to reach the MN. By default, NAT detection is disabled.

replay seconds

(Optional) Sets the replay protection time-stamp value in seconds. A registration received within the router clock time plus or minus 7 is valid.

reverse-tunnel-off

(Optional) Disables support of reverse tunnel by the HA. By default, reverse tunnel support is enabled.

roam-access access-list

(Optional) Controls which MNs are permitted or denied to roam. By default, all specified MNs can roam.

strip-nai-realm

(Optional) Strips the realm part of the Network access identifier (NAI) before authentication is performed. This option is useful if the majority of MNs have the identical realm, for example, in the case of enterprise networks.

suppress-unreachable

(Optional) Disables sending Internet Control Message Protocol (ICMP) unreachable messages to the source when an MN on the virtual network is not registered. By default, ICMP unreachable messages are sent.

local-timezone

(Optional) Uses the local time zone to generate identification fields.

unknown-ha [accept [reply] | deny]

Accepts or denies an unknown HA registration request. The keywords are as follows:

accept—(Optional) HA accepts the registration request with an HA address different from the IP destination of the registration request. The HA address set in the registration reply is that of the IP destination address.

reply—(Optional) HA uses the received HA address in reply.

deny—(Optional) HA denies the registration request with an HA address different from the IP destination of the registration request with error code Unknown HomeAgent. The HA address set in the reject registration reply is that of the IP destination address.


Note This command option can be used in a testing environment when the home agent is in private addressing space behind a NAT gateway.


send-mn-address

Sends the home address as received in the registration request and in the access request messages for the HA Challenge Handshake Authentication Protocol (CHAP).


Note You must configure this keyword in the HA to send radius-server vsa send authentication 3gpp2 attributes.


Note This keyword is available only on PDSN platforms running specific PDSN code images.


Defaults

The command is disabled. Broadcasting is disabled. Reverse tunnel support is enabled. ICMP unreachable messages are sent. NAT detection is disabled.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2(2)XC

The strip-nai-realm and local-timezone keywords were added.

12.2(13)T

The nat-detect keyword was added.

12.3(4)T

The unknown-ha, accept, reply, deny and send-mn-address keywords were added.


Usage Guidelines

This command enables and controls HA services on a router. Changes to service take effect immediately; however, broadcast and lifetime settings for previously registered MNs are unaffected. Tunnels are shared by MNs registered with the same endpoints, so the reverse-tunnel-off keyword also affects registered MNs.

The HA processes registration requests from the MN and sets up tunnels and routes to the CoA. Packets to the MN are forwarded to the visited network.

The HA will forward broadcast packets to MNs if the MNs are registered with the service. However, heavy broadcast traffic uses the CPU of the router.

The HA can control where the MNs roam by the care-of-access keyword, and which MN is allowed to roam by the roam-access keyword.

When a registration request comes in, the HA ignores requests when HA service is not enabled or the security association of the MN is not configured. The latter condition occurs because the security association must be available for the MH authentication extension in the reply. If a security association exists for the FA (IP source address or CoA in the request), the FA is authenticated, and then the MN is authenticated. The Identification field is verified to protect against replay attack. The HA checks the validity of the request (see Table 4) and sends a reply. (Reply codes are listed in Table 5.) A security violation is logged when FA authentication, MH authentication, or identification verification fails. (The violation reasons are listed in Table 6.)

After registration is accepted, the HA creates or updates the mobility binding of the MN, which contains the expiration timer. If no binding existed before this registration, a virtual tunnel is created, a host route to the MN via the care-of address is added to the routing table, and gratuitous ARPs are sent out. For deregistration, the host route is removed from the routing table, the virtual tunnel interface is removed (if no MNs are using it), and gratuitous ARP messages are sent out if the MN is back home. Mobility binding is removed (along with its associated host route and tunnel) when registration lifetime expires or deregistration is accepted.

By default, the HA uses the entire NAI string as the username for authentication (which may be with local security association or retrieved from the AAA server). The strip-nai-realm keyword instructs the HA to strip off the realm part of NAI (if it exists) before performing authentication. Basically, the MN is identified by only the user name part of the NAI. This option is useful if the majority of MNs belong to the same realm, for example, in the case of enterprise networks.

When the packet destined for the MN arrives on the HA, the HA encapsulates the packet and tunnels it to the care-of address. If the Don't Fragment (DF) bit is set in the packet via the ip mobile tunnel path-mtu-discovery global configuration command, the HA will copy the DF bit from the original packet to the new tunnel IP header. This allows the path MTU discovery to set the MTU of the tunnel. Subsequent packets greater than the MTU of the tunnel will be dropped and an ICMP datagram too big message will be sent to the source (correspondent node). If the HA loses the route to the tunnel endpoint, the host route to the MN will be removed from the routing table until the tunnel route is available. Packets destined for the MN without a host route will be sent out the interface (home network) or to the virtual network (see the description of the suppress-unreachable keyword). For subnet-directed broadcasts to the home link, the HA will send a copy to all MNs registered with the broadcast routing option.

Some companies block ICMP datagram too big messages. If the message does not reach the original correspondent node sending the packet, the correspondent node will simply resend the same size packet. To work around this problem, turn off Path MTU Discovery with the no ip mobile tunnel path-mtu-discovery command. The DF bit will not be copied from the original packet and the tunnel packet can be fragmented.

The ip mobile home-agent nat-detect option is supported for MNs using a collocated care-of address and registering through the FA. The MN will use the NAT inside address as the collocated care-of address used in its registration requests. If a MN is using an FA CoA address, the MN can be detected behind a NAT gateway.

The ip mobile home-agent unknown-ha option can be useful in a testing environment when the HA is using a private address behind a NAT gateway. A MN would need to access the HA through the NAT box while it is on a public network domain. However, NAT will translate the destination IP address of the registration request to the private address of the HA. When the HA checks the HA field in the registration request, it does not match one of the interfaces. The packet can not be processed properly and the tunnels are not set up properly. The ip mobile home-agent unknown-ha command allows the HA to accept the unknown (translated) address and process the registration request.

The send-mn-address keyword is available only on PDSN platforms running specific PDSN code images; consult Feature Navigator for your Cisco IOS software release.

The MN requests services from the HA by setting bits in the registration request. Table 4 shows the services the MN can request.

Table 4 HA Registration Bitflags 

Bit Set
Definition

S

Accept with code 1 (no simultaneous binding).

B

Accept. Broadcast can be enabled or disabled.

D

Accept. Tunnel endpoint is a colocated care-of address.

M

Deny. Minimum IP encapsulation is not supported.

G

Accept. GRE encapsulation is supported.

V

Deny if this bit is set.

T

Accept if the reverse-tunnel-off parameter is not set.

reserved

Deny. Reserved bit must not be set.


Table 5 lists the HA registration reply codes. The codes tell the MN whether the registration was accepted or denied. If registration is denied, the reply code gives the reason.

Table 5 HA Registration Reply Codes 

Code
Reason

0

Accept.

1

Accept. No simultaneous bindings.

128

Reason unspecified.

129

Administratively prohibited.

130

Insufficient resource.

131

MN failed authentication.

132

FA failed authentication.

133

Registration identification mismatched (timestamp is off).

134

Poorly formed request.

136

Unknown HA address.

137

Reverse tunnel is unavailable.

138

Reverse tunnel is mandatory and T bit not set.

139

Unsupported encapsulation.

140

Unsupported vendor id or unable to interpret registration request extensions sent by the MN to the home agent.

141

Unsupported vendor id or unable to interpret registration request extensions sent by the FA to the home agent.

142

Active home agent failed authentication.


Table 6 lists security violation codes.

Table 6 Security Violation Codes

Code
Reason

1

No mobility security association.

2

Bad authenticator.

3

Bad identifier.

4

Bad SPI.

5

Missing security extension.

6

Other.

7

Stale request.


Examples

The following example enables broadcast routing and specifies a global registration lifetime of 7200 seconds (2 hours):

ip mobile home-agent broadcast lifetime 7200

Related Commands

Command
Description

ip mobile tunnel

Specifies the setting of tunnels created by Mobile IP.

show ip mobile binding

Displays the mobility binding table.

show ip mobile globals

Displays global information for mobile agents.


ip mobile home-agent aaa user-password

To configure an authentication password for the downloading of security associations from a AAA server, use the ip mobile home-agent aaa user-password command in global configuration mode. To remove the password requirement, use the no form of this command.

ip mobile home-agent aaa user-password {0 password | 7 encrypted-password | password}

no ip mobile home-agent aaa user-password

Syntax Description

0

password

Specifies that an unencrypted password will follow.

The unencrypted (cleartext) password.

7

password

Specifies that an encrypted password will follow.

The encrypted password.

password

The unencrypted (cleartext) password.


Defaults

The default password is cisco.

Command Modes

Global configuration

Command History

Release
Modification

12.3

This command was introduced.


Usage Guidelines

When a mobile node sends a registration request packet to the home agent, Mobile IP requires a security association for registration authentication. Security associations for a mobile node can be configured on the home agent or retrieved by the home agent from a AAA server.

If security associations are retrieved from a AAA server, the AAA access-request packets used to retrieve the security associations require a challenge and response. If the registration request of the mobile node does not contain a challenge and response, the home agent auto-generates a challenge and creates a response using the default password "cisco" unless you specify a different password using the ip mobile home-agent aaa user-password command. In either case, a single password is used for all mobile nodes.

The AAA server will read the challenge in the access-request packet of the mobile node, and using the password of the mobile node that is stored on the AAA server, create the response to the challenge. It then authenticates the mobile node, identified by its IP address (or network access identifier), by comparing the two responses to ensure they are identical. For this reason, the password configured by the ip mobile home-agent aaa user-password command must match the user password in the user profile on the AAA server.

Mobile nodes that include a challenge and response in their registration request, such as in the case of dynamic security association and key distribution, do not use the defined password. Instead, the home agent copies the challenge/response from the registration request into the AAA access-request packet. Thus, a mobile node in this scenario can have a "unique" password.

You can enable or disable password encryption with the service password-encryption command. If this command is enabled, even if the ip mobile home-agent aaa user-password 0 password is used, the password will be encrypted.

Examples

The following example enables the encrypted password "$1$i5Rkls3L0yxzS8t9" for authenticating the downloading of security associations from the AAA server:

ip mobile home-agent aaa user-password 7 $1$i5Rkls3L0yxzS8t9

The following example enables the unencrypted password "pswd2" for authenticating the downloading of security associations from the AAA server:

ip mobile home-agent aaa user-password 0 pwsd2

The following example enables the unencrypted password "pswdmobile" for authenticating the downloading of security associations from the AAA server:

ip mobile home-agent aaa user-password pswdmobile

Related Commands

Command
Description

service password-encryption

Encrypts passwords.


ip mobile home-agent accounting

To enable home agent accounting services on the router, use the ip mobile home-agent accounting command in global configuration mode. To disable these services, use the no form of this command.

ip mobile home-agent accounting {default | list-name}

no ip mobile home-agent accounting {default | list-name}

Syntax Description

default

Uses the listed accounting methods that follow this argument as the default list of methods for accounting services.

list-name

Character string used to name the list of at least one of the accounting methods.


Defaults

The command is disabled.

Command Modes

Global configuration

Command History

Release
Modification

12.2(15)T

This command was introduced.


Usage Guidelines

This command enables and controls home agent accounting services on the router. First, use the aaa accounting global configuration command to define the accounting method list. Next, apply the same accounting method list on the home agent using the ip mobile home-agent accounting global configuration command.

Examples

The following example enables home agent accounting for the list named mobile-list:

ip mobile home-agent accounting mobile-list

Related Commands

Command
Description

aaa accounting

Enables AAA accounting of requested services for billing or security purposes.


ip mobile home-agent nat traversal

To enable NAT traversal support for Mobile IP (MIP) home agents (HAs), use the ip mobile home-agent nat traversal command in global configuration mode. To disable Network Address Translation (NAT) traversal support for MIP for the HA, use the no form of this command.

ip mobile home-agent nat traversal [keepalive keepalive time] [forced {accept | reject}]

no ip mobile home-agent nat traversal

Syntax Description

keepalive keepalive time

(Optional) Configures the keepalive interval in seconds the HA uses in registration replies. When the HA replies with a keepalive interval other than zero, it forces the FA or MN to use this interval. If it replies with an interval of zero, the FA or MN should use its default configured interval. The range is 10 to 600 seconds. The default is 110 seconds.

Note The HA cannot be configured to return a zero keepalive interval in a registration reply.

forced

(Optional) Enables the HA to accept or reject forced UDP tunneling from the mobile node (MN) regardless of the NAT-detection outcome.

accept—Accepts UDP tunneling.

reject—Rejects UDP tunneling.

Note If the forced keyword is not specified, the command defaults to rejecting registration requests where the "force" bit is set in the UDP tunnel extension. MN registration attempts will fail until the MN retires without the "forced" bit set in the UDP tunnel extension. The registration will fail until the MN retries the registration.


Defaults

NAT traversal support for MIP is disabled for the HA.

Command Modes

Global configuration

Command History

Release
Modification

12.3(8)T

This command was introduced.


Usage Guidelines

Enable this command if your MNs will roam behind a NAT-enabled router or firewall.

Examples

The following example shows an HA configured with a keepalive timer set to 56 seconds and forced to accept UDP tunneling.

ip mobile home-agent nat traversal 56 forced accept
ip mobile home-agent replay 255
ip mobile home-agent redundancy Phy1 virtual-network

Related Commands

Command
Description

debug ip mobile

Displays IP mobility activities.

ip mobile foreign-agent nat traversal

Enables NAT UDP traversal support for MIP FAs.

show ip mobile binding

Displays the mobility binding table.

show ip mobile globals

Displays global information about MIP HAs, FAs, and MNs.

show ip mobile tunnel

Displays information about UDP tunneling.

show ip mobile visitor

Displays the table that contains a visitor list of FAs.


ip mobile home-agent redundancy

To configure the home agent for redundancy by using the Hot Standby Router Protocol (HSRP) group name, use the ip mobile home-agent redundancy command in global configuration mode. To remove the address, use the no form of this command.

ip mobile home-agent redundancy hsrp-group-name [[virtual-network] address address]

no ip mobile home-agent redundancy hsrp-group-name [[virtual-network] address address]

Syntax Description

hsrp-group-name

Specifies the HSRP group name.

virtual-network

(Optional) Specifies that the HSRP group is used to support virtual networks.

address address

(Optional) Home agent address.


Defaults

No global home agent addresses are specified.

Command Modes

Global configuration

Command History

Release
Modification

12.0(2)T

This command was introduced.

12.2(8)T

The command changed from ip mobile home-agent standby to ip mobile home-agent redundancy.


Usage Guidelines

The virtual-network keyword specifies that the HSRP group supports virtual networks.


Note Redundant home agents must have identical Mobile IP configurations. You can use a standby group to provide HA redundancy for either physical or virtual networks, but not both at the same time.


When Mobile IP standby is configured, the home agent can request mobility bindings from the peer home agent. When Mobile IP standby is deconfigured, the home agent can remove mobility bindings. Operation of home agent redundancy on physical and virtual networks is described as follows:

Physical network—Only the active home agent will receive registrations on a physical network. It updates the standby home agent. The standby home agent requests the mobility binding table from the active home agent. When Mobile IP standby is deconfigured, the standby home agent removes all bindings, but the active home agent keeps all bindings.

Virtual network—Both active and standby home agents receive registrations if the loopback interface is used; each will update the peer after accepting a registration. Otherwise, the active home agent receives registrations. Both active and standby home agents request mobility binding tables from each other. When Mobile IP standby is deconfigured, the standby or active home agent removes all bindings.

Examples

The following example specifies an HSRP group named SanJoseHA:

ip mobile home-agent redundancy SanJoseHA

Related Commands

Command
Description

show ip mobile globals

Displays global information for mobile agents.


ip mobile home-agent reject-static-address

To configure the home agent to reject registration requests from mobile nodes under certain conditions, use the ip mobile home-agent reject-static-address command in global configuration mode. To disable this service, use the no form of this command.

ip mobile home-agent reject-static-address

no ip mobile home-agent reject-static-address

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values.

Command Modes

Global configuration

Command History

Release
Modification

12.2(8)BY

This command was introduced.

12.2(13)T

This command was integrated into Cisco IOS Release 12.2(13)T.


Usage Guidelines

By default, the home agent gives an alternative authorized address for a mobile node if the home address in the registration request is already in use. If the ip mobile home-agent reject-static-address command is configured, the home agent rejects the registration request with error code 130 (insufficient resources).

Examples

In the following example, the home agent will reject the registration request if the home address proposed in the registration request is in use:

ip mobile home-agent reject-static-address

ip mobile home-agent resync-sa

To configure the home agent to clear out the old cached security associations and requery the AAA server for a new security association when the mobile node fails authentication, use the ip mobile home-agent resync-sa command in global configuration mode. To disable this functionality, use the no form of this command.

ip mobile home-agent resync-sa seconds

no ip mobile home-agent resync-sa seconds

Syntax Description

seconds

Specifies the time in which the home agent will wait to initiate a resynchronization.


Defaults

This command is off by default. The normal behavior of the home agent is to never requery the AAA server for a new security association.

Command Modes

Global configuration

Command History

Release
Modification

12.2

This command was introduced.


Usage Guidelines

You must enable security association caching for the ip mobile home-agent resync-sa command to work. Use the ip mobile host aaa load-sa global configuration command to enable caching of security associations retrieved from a AAA server.

When a security association is downloaded for a mobile node from a AAA server, the security association is time stamped. If the mobile node fails reregistration and the time interval since the security association was cached is greater than sec seconds, the home agent will clear out the old security association and requery the AAA server. If the time period is less than the sec value, the home agent will not requery the AAA server for the security association of the mobile node.

The sec value represents the number of seconds the home agent will consider the downloaded security association synchronized with the AAA server. After that time period, it is considered old and can be replaced by a new security association from the AAA server.

This time-based resynchronization process helps prevent denial-of-service attacks on the AAA server and provides a way to synchronize the home agent's cached security association entry when a change to the security association for the mobile node is made at the AAA server and on the mobile node. By using this process, once the mobile node fails reregistration with the old cached security association, the home agent will clear the cache for that mobile node, and resynchronize with the AAA server.

Examples

In the following example, if a registration fails authentication, the home agent retrieves a new security association from the AAA server if the existing security association was downloaded more than 10 seconds ago:

ip mobile home-agent resync-sa 10

Related Commands

Command
Description

ip mobile host

Configures the mobile node or mobile host group.


ip mobile host

To configure the mobile host or mobile node group, use the ip mobile host command in global configuration mode. To disable these services, use the no form of this command.

ip mobile host {lower [upper] | nai string [static-address {addr1 [addr2] [addr3] [addr4] [addr5] | local-pool name}] [address {addr | pool {local name | dhcp-proxy-client [dhcp-server addr]}]} {interface name | virtual-network network-address mask} [aaa [load-sa [permanent]]] [authorized-pool name] [skip-aaa-reauthentication][care-of-access access-list] [lifetime seconds]

no ip mobile host {lower [upper] | nai string [static-address {addr1 [addr2] [addr3] [addr4] [addr5] | local-pool name}] [address {addr | pool {local name | dhcp-proxy-client [dhcp-server addr]}]} {interface name | virtual-network network-address mask} [aaa [load-sa [permanent]]] [authorized-pool name] [skip-aaa-reauthentication] [care-of-access access-list] [lifetime seconds]

Syntax Description

lower [upper]

One or a range of mobile host or mobile node group IP addresses. The upper end of the range is optional.

nai string

Network access identifier. The NAI can be a unique identifier (username@realm) or a group identifier (@realm).

static-address

(Optional) Indicates that a static IP address is to be assigned to the flows on this NAI. This parameter is not valid if the NAI is a realm.

addr1, addr2, ...

(Optional) One to a maximum of five IP addresses to be assigned using the static-address keyword.

local-pool name

(Optional) Name of the local pool of addresses to use for assigning a static IP address to this NAI.

address

(Optional) Indicates that a dynamic IP address is to be assigned to the flows on this NAI.

addr

(Optional) IP address to be assigned using the address keyword.

pool

(Optional) Indicates that a pool of addresses is to be used in assigning a dynamic IP address.

local name

(Optional) The name of the local pool to use in assigning addresses.

dhcp-proxy-client

(Optional) Indicates that the DHCP request should be sent to a DHCP server on behalf of the mobile node.

dhcp-server addr

(Optional) IP address of the DHCP server.

interface name

When used with DHCP, specifies the gateway address from which the DHCP server should select the address.

virtual-network network-address mask

Indicates that the mobile station resides in the specified virtual network, which was created using the ip mobile virtual-network command.

aaa

(Optional) Retrieves security associations from a AAA (TACACS+ or RADIUS) server. Allows the home agent to download address configuration details from the AAA server.

load-sa

(Optional) Caches security associations after retrieval by loading the security association into RAM. See Table 8 for details on how security associations are cached for NAI hosts and non-NAI hosts.

permanent

(Optional) Caches security associations in memory after retrieval permanently. Use this optional keyword only for NAI hosts.

authorized-pool name

(Optional) Verifies the IP address assigned to the mobile node if it is within the pool specified by the name argument.

skip-aaa-reauthentication

(Optional) When configured, the home agent does not send an access request for authentication for mobile IP re-registration requests. When disabled, the home agent sends an access request for all Mobile IP registration requests.

care-of-access access-list

(Optional) Access list. This can be a named access list or standard access list. The range is from 1 to 99. Controls where mobile nodes roam—the acceptable care-of addresses.

lifetime seconds

(Optional) Lifetime (in seconds). The lifetime for each mobile node (group) can be set to override the global value. The range is from 3 to 65535 (infinite).


Defaults

No host is configured.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2(2)XC

The nai keyword and associated parameters were added.

12.2(13)T

The permanent keyword was added and the command was integrated into Cisco IOS Release 12.2(13)T.

12.3(4)T

The authorized-pool and skip-aaa-reauthentication keywords were added.


Usage Guidelines

This command configures the mobile host or mobile node group (ranging from lower address to upper address) to be supported by the home agent. These mobile nodes belong to the network on an interface or a virtual network (via the ip mobile virtual-network command). The security association for each mobile host must be configured using the ip mobile secure command or downloaded from a AAA server.

All hosts must have security associations for registration authentication. Mobile nodes can have more than one security association. The memory consumption calculations shown in Table 7 are based on the assumption of one security association per mobile node. Caching behavior of security associations differs between NAI and non-NAI hosts as described in Table 8.

The nai keyword allows you to specify a particular mobile node or range of mobile nodes. The mobile node can request a static IP address (static-address keyword), which is configured using the addr1 variable (for a specific address) or the local-pool keyword (for an IP address from an address pool; the requested address must be in the pool). Or, the mobile node can request a dynamic address (address keyword), which is configured using the addr variable (for a specific address) or the pool keyword (for an IP address from a pool or DHCP server). If this command is used with the Packet Data Serving Node (PDSN) proxy Mobile IP feature and a realm is specified in the ip mobile proxy-host nai command, then only a pool of addresses can be specified in this command.

The address pool can be defined by a local pool or by use of a DHCP proxy client. For DHCP, the interface name keyword and argument combination specifies the gateway address from which the DHCP server should select the address and the dhcp-server keyword specifies the DHCP server address. The NAI is sent in the client-id option of the DHCP packet and can be used to provide dynamic DNS services.

You can also use this command to configure the static IP address or address pool for multiple flows with the same NAI. A flow is a set of {NAI, IP address}.

Security associations can be stored using one of three methods:

On the router

On the AAA server, retrieve security association each time registration comes in (aaa optional keyword)

On the AAA server, retrieve and cache security association (aaa load-sa option)

Each method has advantages and disadvantages, which are described in Table 7.

Table 7 Methods for Storing Security Associations 

Storage Method
Advantage
Disadvantage

On the router

Security association is in router memory, resulting in fast lookup.

For home agents supporting fewer than 1500 mobile nodes, this provides optimum authentication performance and security (keys never leave router).

NVRAM of router is limited, cannot store many security associations. Each security association configuration takes about 80 bytes. For 125 KB NVRAM, you can store about 1500 security associations on a home agent.

On the AAA server, retrieve security association each time registration comes in

Central administration and storage of security association on AAA server.

If keys change constantly, administration is simplified to one server, latest keys always retrieved during registration.

Router memory (DRAM) is conserved. Router will need memory only to load in a security association, and then release the memory when done.

Requires network to retrieve security association, slower than other storage methods, and dependent on network and server performance.

Multiple home agents that use one AAA server, which can become the bottleneck, can get slow response.

Key can be snooped if packets used to retrieve from AAA are not encrypted (for example, using RADIUS or unencrypted TACACS+ mode).

On the AAA server, retrieve and store security association

AAA acts as an offload configuration server, security associations are loaded into router DRAM, which is more abundant (for example, 16 MB, 32 MB, 64 MB) when the first registration comes in. Each security association takes only about 50 bytes of DRAM, so 10,000 mobile nodes will use up 0.5 MB.

If keys remain fairly constant, once security associations are loaded, home agent authenticates as fast as when stored on the router.

Only security associations that are needed are loaded into router memory. Mobile nodes that never register will not waste memory.

If keys change on the AAA server after the mobile node registered, then you need to use clear ip mobile secure command to clear and load in new security association from AAA, otherwise the security association of the router is stale.


The caching behavior of security associations for NAI hosts and non-NAI hosts is described in Table 8.

Table 8 Caching Behavior for Security Associations 

Keyword Option
NAI Hosts
Non-NAI Hosts

aaa

Security associations are deleted after authentication and are not cached.

Security associations are deleted after authentication and are not cached.

aaa load-sa

The security association is cached while the mobile node is registered. If the mobile node's registration is deleted, the security association is removed.

Security associations are cached permanently.

aaa load-sa permanent

Security associations are cached permanently after being retrieved from the AAA server.


Examples

The following example configures a mobile node group to reside on virtual network 20.0.0.0 and retrieve mobile node security associations from a AAA server every time the mobile node registers:

ip mobile host 20.0.0.1 20.0.0.3 virtual-network 20.0.0.0 aaa

The following example configures a mobile node group to reside on virtual network 10.99.1.0 and retrieve and cache mobile node security associations from a AAA server. The cached security association is then used for subsequent registrations.

ip mobile host 10.99.1.1 10.99.1.100 virtual-network 10.99.1.0 aaa load-sa

The following example configures a local pool of dynamic addresses to be used in assigning IP addresses to mobile nodes in the cisco.com domain:

ip mobile host nai @cisco.com address pool local mobilenodes virtual-network 9.0.0.0 
255.0.0.0 aaa lifetime 180

The following example configures a local pool of dynamic addresses to be used in assigning IP addresses to mobile nodes in the cisco.com domain. The security associations that are retrieved from the AAA server are cached as long as the binding is present and are deleted on the home agent when the binding is removed (due to manual clearing of the binding or lifetime expiration).

ip mobile host nai @cisco.com address pool local mobilenodes virtual-network 10.2.0.0 
255.255.0.0 aaa load-sa lifetime 180

The following example configures a local pool of static addresses to be used in assigning IP addresses to mobile nodes in the cisco.com domain:

ip mobile host nai @cisco.com static-address local-pool mobilenodes

The following example configures a local pool of dynamic addresses to be used in assigning IP addresses to mobile nodes in the cisco.com domain. The security associations that are retrieved from the AAA server are cached permanently until cleared manually.

ip mobile host nai @cisco.com address pool local mobilenodes virtual network 10.2.0.0 
255.255.0.0 aaa load-sa permanent lifetime 180

The following example configures the DHCP proxy client to use a DHCP server located at 10.1.2.3 to allocate a dynamic home address:

ip mobile host nai @dhcppool.com address pool dhcp-proxy-client dhcp-server 10.1.2.3 
interface FastEthernet 0/0

Related Commands

Command
Description

aaa authorization ipmobile

Authorizes Mobile IP to retrieve security associations from the AAA server using TACACS+ or RADIUS.

clear ip mobile secure

Clears and retrieves remote security associations.

ip mobile proxy-host

Locally configures the proxy Mobile IP attributes

ip mobile secure

Specifies the mobility security associations for mobile host, visitor, home agent, and foreign agent.

show ip mobile host

Displays mobile node counters and information.


ip mobile mobile-networks

To associate one or more networks with a mobile router configured as a mobile host and enter mobile networks configuration mode, use the ip mobile mobile-networks command in global configuration mode. To disassociate the networks from the mobile router, use the no form of this command.

ip mobile mobile-networks lower [upper]

no ip mobile mobile-networks lower [upper]

Syntax Description

lower [upper]

Range of mobile host or mobile node group IP addresses. The upper end of the range is optional but can only be used for dynamic registration of mobile networks. Static mobile network configurations are not permitted for a range of hosts.


Defaults

No default behavior or values.

Command Modes

Global configuration

Command History

Release
Modification

12.2(4)T

This command was introduced.

12.2(13)T

The upper argument was added to allow a range of mobile host or mobile node group addresses.


Usage Guidelines

The home agent supports mobile routers configured with the mobile networks that are roaming with the mobile routers.

The lower [upper] arguments associate the mobile networks with the IP address of the mobile router, which was configured using the ip mobile host command. You can use the upper range only with dynamic mobile network registration. Static mobile network configurations are not permitted for a range of hosts.

You can configure the home agent to dynamically learn of the mobile networks during registration as shown in the following example:

ip mobile host 10.0.0.1 10.0.0.10 virtual-networks 10.0.0.0 255.0.0.0
ip mobile mobile-networks 10.0.0.1 10.0.0.10
!dynamic registration
 register

You can configure the home agent to learn of the mobile networks through static configuration as shown in the following example:

ip mobile host 10.0.0.1 virtual-networks 10.0.0.0 255.0.0.0
ip mobile host 10.0.0.2 virtual-networks 10.0.0.0 255.0.0.0
!
ip mobile mobile-networks 10.0.0.1
!static configuration
 network 172.16.1.0 255.255.255.0

ip mobile mobile-networks 10.0.0.2
!static configuration
 network 172.16.2.0 255.255.255.0

You cannot configure the range as shown in the following static configuration:

!static configuration not permitted for range of hosts
ip mobile mobile-networks 10.0.0.1 10.0.0.10
 network 172.16.2.0 

The mobile router configuration is allowed only for one mobile router or an entire range of mobile routers in the mobile host group, exclusively. You cannot configure a partial range of mobile routers as shown in the following example:

ip mobile host 10.0.0.1 10.0.0.10 virtual-network 10.0.0.0 255.0.0.0
!Partial range shown below is prohibited
ip mobile mobile-networks 10.0.0.1 10.0.0.3
 register

You cannot combine full ranges and partial ranges of IP addresses in a configuration as shown in the following example:

ip mobile host 10.0.0.1 10.0.0.10 virtual-network 10.0.0.0 255.0.0.0
ip mobile mobile-networks 10.0.0.1 10.0.0.10
 register
ip mobile mobile-networks 10.0.0.2 
 network 172.16.2.0 255.255.255.0

Examples

The following example configures the mobile host, which is a mobile router at 10.1.1.10, and associates it with the mobile networks that it is supporting:

ip mobile host 10.1.1.10 virtual-network 10.0.0.0 255.0.0.0
ip mobile mobile-networks 10.1.1.10
 network 172.6.2.0 255.255.255.0
ip mobile secure host 10.1.1.10 spi 100 key hex 12345678123456781234567812345678

The following example shows the mobile router configured for both static and dynamic mobile networks:

ip mobile host 10.1.1.10 virtual-network 10.0.0.0 255.0.0.0
ip mobile mobile-networks 10.1.1.10
 network 172.16.1.0 255.255.255.0
 register

Related Commands

Command
Description

ip mobile host

Associates a mobile router with mobile networks.

register (mobile router)

Dynamically registers the mobile networks with the home agent.

show ip mobile mobile-networks

Displays a list of mobile networks associated with the mobile router.


ip mobile prefix-length

To append the prefix-length extension to the advertisement, use the ip mobile prefix-length command in interface or global configuration mode. To restore the default, use the no form of this command.

ip mobile prefix-length

no ip mobile prefix-length

Syntax Description

This command has no arguments or keywords.

Defaults

The prefix-length extension is not appended.

Command Modes

Interface configuration and global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.3(11)T

Global configuration mode was added.


Usage Guidelines

The prefix-length extension is used for movement detection. When a mobile node registered with one foreign agent receives an agent advertisement from another foreign agent, the mobile node uses the prefix-length extension to determine whether the advertisements arrived on the same network. The mobile node needs to register with the second foreign agent if it is on a different network. If the second foreign agent is on the same network, reregistration is not necessary.

Examples

The following example appends the prefix-length extension to agent advertisements sent by a foreign agent:

ip mobile prefix-length

Related Commands

Command
Description

show ip mobile interface

Displays advertisement information for interfaces that are providing foreign agent service or are home links for mobile nodes.


ip mobile proxy-host

To locally configure the proxy Mobile IP attributes, use the ip mobile proxy-host command in global configuration mode. To remove the configuration, use the no form of this command.

ip mobile proxy-host nai username@realm [flags rrq-flags] [home-agent ip-address] [home-addr home-address] [lifetime seconds] [local-timezone]

no ip mobile proxy-host nai username@realm [flags rrq-flags] [home-agent ip-address] [home-addr home-address] [lifetime seconds] [local-timezone]

Syntax Description

nai username@realm

Network access identifier.

flags rrq-flags

(Optional) Registration request flags.

home-agent ip-address

(Optional) IP address of the home agent.

home-addr home-address

(Optional) Home IP address of the mobile node.

lifetime seconds

(Optional) Global registration lifetime for a mobile node. Note that this can be overridden by the individual mobile node configuration. Values are from 3 to 65535 (infinity). Default is 36000 seconds (10 hours). Registrations requesting a lifetime greater than this value will still be accepted, but will use this lifetime value.

local-timezone

(Optional) Adjusts the UTC time based on the local time zone configured and uses the adjusted time for proxy mobile IP registration.


Defaults

No security association is specified.

Command Modes

Global configuration

Command History

Release
Modification

12.2(2)XC

This command was introduced.

12.3(4)T

This command was integrated into Cisco IOS Release 12.3(4)T for Packet Data Serving Node (PDSN) platforms.


Usage Guidelines

This command is only available on PDSN platforms running specific PDSN code images; consult Feature Navigator for your Cisco IOS software release.

All proxy Mobile IP attributes can be retrieved from the AAA server. You can use this command to configure the attributes locally.

If only a realm is specified, the home address cannot be specified.

Examples

The following example configures the Mobile IP proxy host with an IP address of 10.3.3.1 and a lifetime value of 6000 seconds:

ip mobile proxy-host nai moiproxy1@cisco.com flags 40 home-agent 10.3.3.1 lifetime 6000

Related Commands

Command
Description

ip mobile host

Configures the mobile host or mobile node group.

ntp server

Allows the system clock to be synchronized by a time server.

ip mobile secure

Configures the mobility security associations for mobile host, mobile visitor, foreign agent, home agent, or proxy mobile host.

show ip mobile proxy

Displays information about the proxy host configuration.


ip mobile registration-lifetime

To set the registration lifetime value advertised, use the ip mobile registration-lifetime command in interface or global configuration mode.

ip mobile registration-lifetime seconds

Syntax Description

seconds

Lifetime in seconds. Range is from 3 to 65535 (infinity).


Defaults

36000 seconds

Command Modes

Interface and global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.3(11)T

Global configuration mode was added.


Usage Guidelines

This command allows an administrator to control the advertised lifetime on the interface. The foreign agent uses this command to control duration of registration. Visitors requesting longer lifetimes will be denied.

Examples

The following example sets the registration lifetime to 10 minutes on interface Ethernet 1 and 1 hour on interface Ethernet 2:

interface e1
 ip mobile registration-lifetime 600
interface e2
 ip mobile registration-lifetime 3600

Related Commands

Command
Description

show ip mobile interface

Displays advertisement information for interfaces that are providing foreign agent service or are home links for mobile nodes.


ip mobile router

To enable the mobile router and enter mobile router configuration mode, use the ip mobile router command in global configuration mode. To disable the mobile router, use the no form of this command.

ip mobile router

no ip mobile router

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Global configuration

Command History

Release
Modification

12.2(4)T

This command was introduced.


Usage Guidelines

The mobile router is a router that operates as a mobile node. The mobile router can roam from its home network and still provide connectivity for devices on its networks. The mobile networks are locally attached to the router.

Examples

The following example enables the mobile router:

ip mobile router

Related Commands

Command
Description

show ip mobile router

Displays configuration information and monitoring statistics about the mobile router.


ip mobile router-service

To enable mobile router service on an interface, use the ip mobile router-service command in interface configuration mode. To disable this service, use the no form of this command.

ip mobile router-service {hold-down [foreign-agent seconds | reassociate msec] | roam [priority value] | solicit [interval seconds] [retransmit initial minimum maximum seconds retry number]}

no ip mobile router-service {hold-down [foreign-agent seconds | reassociate msec] | roam [priority value] | solicit [interval seconds] [retransmit initial minimum maximum seconds retry number]}

Syntax Description

hold-down

Specifies a delay period for mobile router registration.

foreign-agent seconds

(Optional) Time (in seconds) to wait before the mobile router registers to agents heard on an interface. Thedefault is zero. The range is from 0 to 3600 seconds.

reassociate msec

(Optional) Specifies the delay (in milliseconds), after receiving a linkDown trap, that the mobile router waits for a linkUp trap. The default is 1000 msec. The range is from 0 to 5000 seconds.

roam

Enables the mobile router interface to roam.

priority value

(Optional) Priority value that is compared among multiple configured interfaces to select the interface in which to send the registration request. When multiple interfaces have highest priority, the highest bandwidth is the preferred choice. When multiple interfaces have the same bandwidth, the interface with the highest IP address is preferred. The range is from 0 to 255; the default is 100. Higher values equate to a higher priority.

solicit

Instructs the mobile router to send agent solicitation messages periodically.

interval seconds

(Optional) Interval (in seconds) to wait before the mobile router sends the next agent solicitation message after an advertisement is received on an interface. The range is from 1 to 65535 seconds; the default interval is
600 seconds (10 minutes).

retransmit initial

(Optional) Wait period before a retransmission of a registration request when no reply is received. The range is from 10 to 10000 milliseconds
(10 seconds); the default is 1000 milliseconds (1 second).

minimum

(Optional) Minimum wait period (in seconds) before retransmission of a registration request when no reply is received.

maximum seconds

(Optional) Maximum wait period (in seconds) before retransmission of a registration request when no reply is received. Each successive retransmission timeout period is twice the previous period, as long as that is less than the maximum value.

retry number

(Optional) Number of times to retry sending the retransmission request. Retransmission stops after the maximum number of retries are attempted. The range is from 0 to 10; the default retry is 3. A value of 0 means no retransmission.


Defaults

hold-down foreign agent seconds: zero
hold-down reassociate msec: 1000
priority value: 100
interval seconds: 600 seconds
retransmit initial minimum maximum seconds: 1000 milliseconds (1 second)
retry number : Three retries

Command Modes

Interface configuration

Command History

Release
Modification

12.2(4)T

This command was introduced.

12.3(14)T

The foreign-agent seconds and reassociate msec keywords and arguments were added.


Usage Guidelines

The mobile router discovers home agents and foreign agents by receiving agent advertisements.


Note In release 12.3(14)T, the ip mobile router-service hold-down command was changed to the ip mobile  router-service hold-down foreign-agent command. The previous version of the command is still accepted but the new command will appear in the running configuration.


When a wireless link connected to an interface is lossy, the mobile router must not immediately register with the foreign agent even when heard on a preferred interface. The ip mobile router-service hold-down foreign-agent seconds command allows existing communications to continue with mobile networks while the mobile router gauges the quality of the link to the new foreign agent.

The ip mobile router-service solicit command instructs the mobile router to send agent solicitation messages periodically. Some networks only send out agent advertisements periodically or when solicited. For networks on which agents do not advertise periodically, this function must be enabled to detect agents. The mobile router always sends solicitation messages when roaming interfaces come up.

If a mobile router interface is configured for solicitations, you should set both ip irdp maxadvertinterval seconds and ip irdp holdtime seconds to 0 seconds on the foreign agent. These settings ensure that the foreign agent will not send out any IRDP advertisements unless solicited. If a foreign agent or home agent are sending IRDP advertisements periodically, then a solicitation will trigger the agent to send an advertisement immediately instead of at the next time interval.

The solicit timer for the ip mobile router-service solicit command is reset and no solicitation is sent out on the roaming interface if the mobile router receives an advertisement from a foreign agent before the solicit timer expires. For example, if the mobile router is configured to solicit every 10 seconds and the foreign agent advertises every 3 seconds, the mobile router will never solicit.

Use the ip mobile router-service hold-down reassociate msec command to specify the interval of time that the mobile router will wait, after receiving an SNMP linkDown trap, for a linkUp trap from the Wireless Mobile Interface Card (WMIC) indicating that the wireless link is available for use. This hold-down delay should be long enough for the WMIC to establish connectivity with a new AP or bridge when roaming.

Use the show ip mobile router agent command to display agents learned from advertisements and the mobile router's available CCoAs. Use the show ip mobile router interface command to display the configuration of the interfaces used for roaming.

Examples

The following example configures roaming interfaces, solicitation services, and hold-down timers on serial interface 0 and roaming interfaces and hold-down timers on Ethernet interface 0 of the mobile router.

In this example, the mobile router has two interfaces. The serial interface is connected to a serial interface of a foreign agent and the Ethernet interface is connected to an Ethernet interface of a foreign agent. The mobile router will prefer to register on the Ethernet interface if possible because it has a higher priority than the serial interface. If the mobile router does not receive any agent advertisements on the Ethernet interface, it will use the serial interface to solicit foreign agents.

If the Ethernet interface hears a new foreign agent advertisement after the mobile router has already registered using the serial interface, it will wait the duration of the hold-down timer (20 seconds) before registering with the foreign agent on the Ethernet interface. The ip mobile router-service hold-down foreign-agent seconds command allows communications to continue with mobile networks while the mobile router gauges the quality of the link to the new foreign agent. The Ethernet interface is configured with a higher priority so the mobile router prefers to register with this interface.

Once it receives an agent advertisement on the Ethernet interface, it will use the Ethernet interface to register to its home agent.

interface s0
  ip mobile router-service roam 
! s0 solicits every 5 seconds after last advertisement received on the interface
  ip mobile router-service solicit interval 5
  ip mobile router-service hold-down foreign-agent 20
interface e0
  ip mobile router-service roam priority 101
  ip mobile router-service hold-down foreign-agent 20

In the following example, the mobile router is configured to receive dynamic CCoA from DHCP. The mobile router will wait 2000 milliseconds for the SNMP linkUp trap from the WMIC indicating that layer 2 has reassociated. This interval of time allows the mobile router to roam and still maintain wireless connectivity.

interface FastEthernet0
 ip address dhcp
 ip dhcp client mobile renew count 3 interval 20
 ip mobile router-service roam
 ip mobile router-service collocated
 ip mobile router-service hold-down reassociate 2000

Related Commands

Command
Description

show ip mobile router agent

Displays information about the agents for the mobile router.

show ip mobile router interface

Displays information about the interface that the mobile router is using for roaming.


ip mobile router-service collocated

To enable static or dynamic collocated care-of address (CCoA) processing on a mobile router interface, use the ip mobile router-service collocated command in interface configuration mode. To disable static or dynamic CCoA processing, use the no form of this command.

ip mobile router-service collocated [gateway ip-address] [ccoa-only]

no ip mobile router-service collocated [gateway ip-address] [ccoa-only]

Syntax Description

gateway ip-address

(Optional) Next hop IP address for the mobile router to forward packets. The gateway ip-address combination is only seen while configuring an Ethernet interface.

ccoa-only

(Optional) Enables the interface to use CCoA processing only.


Defaults

No default behavior or values

Command Modes

Interface configuration

Command History

Release
Modification

12.2(15)T

This command was introduced.

12.3(4)T

The ccoa-only keyword was added. Dynamic CCoA functionality was added.


Usage Guidelines

The primary IP address of the interface is used as the CCoA. The interface must already be configured as a roaming interface using the ip mobile router-service roam interface configuration command for both static and dynamic CCoA processing.

The mobile router can register with the home agent using a CCoA that was acquired dynamically via the IP Control Protocol (IPCP).

The gateway IP address is the next-hop IP address for registration packets. Upon successful registration, this address will be used as the default gateway and default route.

You need not specify the gateway ip-address combination if using a serial interface. The gateway ip-address combination is required on all non point-to-point interfaces such as Ethernet LANs and must be on the same logical subnet as the primary interface IP address.

You can configure the mobile router interface to register only its CCoA and ignore foreign agent advertisements by using the ip mobile router-service collocated ccoa-only option. Using this command on an interface already registered with a foreign agent CoA will cause the mobile router to re-register immediately with a CCoA.

Using the no ip mobile router-service collocated ccoa-only command on an interface already registered with a CCoA will cause the interface to deregister its CCoA and begin foreign agent discovery.

Examples

The following example enables static CCoA processing on a mobile router interface:

interface FastEthernet0/0
! Primary IP address is the static CCoA
 ip address 172.21.58.23 255.255.255.0
 ip mobile router-service roam
! Gateway IP address is next-hop destination
 ip mobile router-service collocated gateway 172.21.58.1

The following example enables dynamic CCoA processing on a mobile router interface:

interface Serial 3/1
 ip address negotiated
 encapsulation ppp
 ip mobile router-service roam
 ip mobile router-service collocated

The following example enables static CCoA-only processing. The interface will not listen to foreign agent advertisements.

interface Ethernet 1/0
 ip address 10.0.1.1 255.255.255.0
 ip mobile router-service roam
 ip mobile router-service collocated gateway 10.0.1.2 ccoa-only
 ip mobile router-service collocated registration retry 30

The following example enables dynamic CCoA-only processing. The interface will not listen to foreign agent advertisements.

interface Serial 1/0
 ip address negotiated
 encapsulation ppp
 ip mobile router-service roam
 ip mobile router-service collocated ccoa-only

Related Commands

Command
Description

ip mobile router-service collocated registration retry

Configures the time period that the mobile router waits before sending another registration request after a registration failure.

ip mobile router-service roam

Enables the mobile router to discover on which configured interface it will discover foreign agents.


ip mobile router-service collocated registration retry

To configure the time period that the mobile router waits before sending another registration request after a registration failure, use the ip mobile router-service collocated registration retry command in interface configuration mode. To disable this functionality, use the no form of this command.

ip mobile router-service collocated registration retry seconds

no ip mobile router-service collocated registration retry

Syntax Description

seconds

Retry interval (in seconds) for registration requests. The range is from 1 to 65535.


Defaults

60 seconds

Command Modes

Interface configuration.

Command History

Release
Modification

12.2(15)T

This command was introduced.


Usage Guidelines

An interface configured for static collocated care-of address (CCoA) will not have foreign agent advertisements to use to trigger new registration attempts. Any foreign agent advertisements detected on that interface are ignored.

The default retry value is 60 seconds. You need to use this command only when a different retry interval is desired.

Examples

The following example shows that the mobile router will wait 30 seconds before sending another registration request after a registration failure:

interface FastEthernet0/0
! Primary IP address is the CCoA
 ip address 172.21.58.23 255.255.255.0
 ip mobile router-service roam
 ip mobile router-service collocated gateway 172.21.58.1
 ip mobile router-service collocated registration retry 30

Related Commands

Command
Description

ip mobile router-service collocated

Enables static CCoA processing on a mobile router interface.


ip mobile router-service tunnel mode

To set the encapsulation mode for a mobile router interface, use the ip mobile router-service tunnel mode command in interface configuration mode. To restore the default encapsultion mode on an interface, use the no form of this command.

ip mobile router-service tunnel mode {gre | ipip}

no ip mobile router-service tunnel mode

Syntax Description

gre

Specifies that the mobile router will attempt to register with Generic Routing Encapsulation (GRE) on the interface.

ipip

Specifies that IP-in-IP encapsulation will be used on the interface.


Defaults

The default encapsulation mode for Mobile IP is IP-in-IP encapsulation.

Command Modes

Interface configuration

Command History

Release
Modification

12.3(7)T

This command was introduced.


Usage Guidelines

If the ip mobile router-service tunnel mode gre command is configured, the mobile router will request GRE encapsulation in the registration request only if the foreign agent (FA) advertises that it is capable of GRE encapsulation (the G bit is set in the advertisement). If the registration request is successful, packets will be tunneled using GRE.

If the ip mobile router-service tunnel mode gre command is enabled and collocated care-of address (CCoA) is configured, the mobile router will attempt to register with the home agent (HA) using GRE encapsulation. If the registration request is successful, packets will be tunneled using GRE.

If the mobile router receives a denied registration reply with error code 72 (foreign agent required encapsulation unavailable) or error code 139 (home agent unsupported encapsulation), the mobile router will send another registration request with the G bit unset and IP-in-IP encapsulation will be used.

The no ip mobile router-service tunnel mode command instructs the mobile router to revert to the default encapsulation mode and register with IP-in-IP encapsulation.


Note If an encapsulation type is configured on an interface using the ip mobile router-service tunnel mode command, that encapsulation type takes precedence over the global encapsulation type configured with the tunnel mode gre command.


Once GRE encapsulation is enabled, GRE keepalives can be configured on an interface using the keepalive command. GRE keepalives check for a failure in the end-to-end tunnel at a configurable interval. If the connection to the HA is lost, the mobile router will attempt to reregister. GRE keepalives must be configured on the mobile router only—no configuration is required on the HA.


Note If the GRE keepalive messages time out, indicating an interruption in the end-to-end tunnel, only the mobile router will tear down the GRE tunnel. The HA will not tear down its side of the tunnel.


Examples

The following example configures GRE encapsulation and GRE keepalive messages on an interface of a mobile router:

interface FastEthernet0/0
 ip address 10.52.52.2 255.255.255.0
 ip mobile router-service roam
 ip mobile router-service tunnel mode gre
!
interface tunnel 121
 keepalive 5 3
!
ip mobile router
 template tunnel 121

Related Commands

Command
Description

keepalive

Enables keepalive packets and specifies the number of times that the Cisco IOS software tries to send keepalive packets without a response before bringing down the interface or before bringing the tunnel protocol down for a specific interface.

tunnel mode gre

Sets the global encapsulation mode on all roaming interfaces of a mobile router to GRE.


ip mobile secure aaa-download

To specify that authentication, authorization, and accounting (AAA) mobility security associations (SAs) are downloaded from the AAA server and the rate at which the information is downloaded, use the ip mobile secure aaa-download command in global configuration mode. To delete the AAA download rate, use the no form of this command.

ip mobile secure aaa-download rate seconds

no ip mobile secure aaa-download rate seconds

Syntax Description

rate

Rate at which the AAA SA is downloaded.

seconds—Download rate, in seconds. The range is from 1 to 100.


Defaults

No AAA SAs are downloaded.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.


Usage Guidelines

SAs are downloaded from a AAA server on the first use. This command allows the home agent (HA) to prepopulate an SA table.

Examples

The following example shows a download rate of 35 seconds:

ip mobile secure aaa-download rate 35

Related Commands

Command
Description

ip mobile host

Configures the mobile host or mobile node group.

ip mobile proxy-host

Configures the proxy Mobile IP attributes.

ip mobile secure foreign-agent

Configures the mobility SAs for an FA.

ip mobile secure home-agent

Configures the mobility SAs for an HA.

ip mobile secure host

Configures the mobility SAs for a mobile host.

ip mobile secure mn-aaa

Specifies non-standard SPI values in the MN-AAA authentication extension that need to be accepted by the home agent or foreign agent.

ip mobile secure proxy-host

Configures the mobility SAs for a proxy host.

ip mobile secure visitor

Configures the mobility SAs for a visitor.

ntp server

Allows the system clock to be synchronized by a time server.

show ip mobile secure

Displays the mobility SAs for a mobile host, mobile visitor, FA, or HA.


ip mobile secure foreign-agent

To specify the mobility security associations (SAs) for a foreign agent (FA), use the ip mobile secure foreign-agent command in global configuration mode. To remove the mobility SAs, use the no form of this command.

ip mobile secure foreign-agent lower-address [upper-address] {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}]

no ip mobile secure foreign-agent lower-address [upper-address] {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}]

Syntax Description

lower-address

IP address of an FA or lower range of IP address pool.

upper-address—(Optional) Upper range of IP address pool. If specified, SAs for multiple FAs are configured.

Note The upper-address value must be greater than the lower-address value.

inbound-spi

Bidirectional 4-byte security parameter index (SPI) used for authenticating inbound registration packets.

spi-in—Index for inbound registration packets. The range is from 100 to ffffffff.

outbound-spi

SPI used for calculating the authenticator in outbound registration packets.

spi-out—Index for outbound registration packets. The range is from 100 to ffffffff.

spi

SPI authenticates a peer. The argument and keyword are as follows:

hex-value—SPI expressed as a hexadecimal number. The range is from 100 to ffffffff.

Note Cisco recommends that you use hexadecimal values instead of decimal values for interoperability.

decimal—Decimal SPI. The argument is as follows:

decimal-value—SPI expressed as a decimal number. The range is from 256 to 4294967295.

key

Security key. The arguments and keywords are as follows:

ascii string—Security key expressed as an ASCII string. A maximum of 32 characters is allowed. No spaces are allowed.

hex string—Security key expressed in hexadecimal digits. A maximum of 32 hex digits is allowed. The range is from 100 to ffffffff. No spaces are allowed.

replay timestamp

(Optional) Specifies the number of seconds that the router uses for replay protection.

seconds—Time, in seconds, that a router uses for replay protection. The range is from plus or minus 255. The default is plus or minus 7.

Note The registration packet is considered "not replayed" if the time stamp in the packet is within plus or minus the configured number of seconds of the router clock.

algorithm

(Optional) Algorithm used to authenticate messages during registration. The keywords are as follows:

md5 mode—Message Digest 5 (MD5) mode used to authenticate packets during registration.

prefix-suffix—Wrapped registration information for authentication (for example, key registration information key) that calculates the message digest.

Note Cisco no longer recommends this method of authentication, but it is retained for backward compatibility.

hmac-md5—Hash-based Message Authentication Code (HMAC) MD5.

Note The HMAC-MD5 authentication algorithm or MD5 (prefix-suffix) authentication algorithm is mandatory for mobile-home authentication (MHAE), mobile-foreign authentication (MFAE), or foreign-home authentication (FHAE).


Defaults

No SA is specified for FAs.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2

The lower-address and upper-address arguments were added.

12.2(13)T

The hmac-md5 keyword was added.


Usage Guidelines

The SA consists of an entity address, SPI, key, replay protection method, authentication algorithm, and authentication algorithm mode (prefix-suffix).

On a FA, the SA of the visiting mobile host and the SA of the home agent (HA) are optional. Multiple SAs for each entity can be configured.

The SA of a visiting mobile host on the MFAE and the SA of the HA on the FHAE are optional on the FA as long as they are not specified on the other entity. Multiple SAs for each entity can be configured.


Note NTP is not required for operation, but NTP can be used to synchronize time for all parties.


Examples

The following example shows the configuration of an FA with an IP address of 209.165.200/254:

ip mobile secure foreign-agent 209.165.200/254 inbound-spi 203 outbound-spi 150 key 
hex ffffffff

Related Commands

Command
Description

ip mobile host

Configures the mobile host or mobile node group.

ip mobile proxy-host

Configures the proxy Mobile IP attributes.

ip mobile secure aaa-download

Configures the rate at which AAA security associations are downloaded.

ip mobile secure home-agent

Configures the mobility SAs for an HA.

ip mobile secure host

Configures the mobility SAs for a mobile host.

ip mobile secure mn-aaa

Specifies non-standard SPI values in the MN-AAA authentication extension that need to be accepted by the home agent or foreign agent.

ip mobile secure proxy-host

Configures the mobility SAs for a proxy host.

ip mobile secure visitor

Configures the mobility SAs for a visitor.

show ip mobile secure

Displays the mobility SAs for a mobile host, mobile visitor, FA, or HA.


ip mobile secure home-agent

To specify the mobility security associations (SAs) for a home agent (HA), use the ip mobile secure home-agent command in global configuration mode. To remove the mobility SAs, use the no form of this command.

ip mobile secure home-agent lower-address [upper-address] {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}]

no ip mobile secure home-agent lower-address [upper-address[ {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}]

Syntax Description

lower-address

IP address of an HA or lower range of IP address pool.

upper-address—(Optional) Upper range of IP address pool. If specified, SAs for multiple HAs are configured.

Note The upper-address value must be greater than the lower-address value.

inbound-spi

Bidirectional 4-byte security parameter index (SPI) used for authenticating inbound registration packets.

spi-in—Index for inbound registration packets. The range is from 100 to ffffffff.

outbound-spi

SPI used for calculating the authenticator in outbound registration packets.

spi-out—Index for outbound registration packets. The range is from 100 to ffffffff.

spi

SPI authenticates a peer. The argument and keyword are as follows:

hex-value—SPI expressed as a hexadecimal number. The range is from 100 to ffffffff.

Note Cisco recommends that you use hexadecimal values instead of decimal values for interoperability.

decimal—Decimal SPI. The argument is as follows:

decimal-value—SPI expressed as a decimal number. The range is from 256 to 4294967295.

key

Security key. The arguments and keywords are as follows:

ascii string—Security key expressed as an ASCII string. A maximum of 32 characters is allowed. No spaces are allowed.

hex string—Security key expressed in hexadecimal digits. A maximum of 32 hex digits is allowed. The range is from 100 to ffffffff. No spaces are allowed.

replay timestamp

(Optional) Specifies the number of seconds that the router uses for replay protection.

seconds—Time, in seconds, that a router uses for replay protection. The range is from plus or minus 255. The default is plus or minus 7.

Note The registration packet is considered "not replayed" if the time stamp in the packet is within plus or minus the configured number of seconds of the router clock.

algorithm

(Optional) Algorithm used to authenticate messages during registration. The keywords are as follows:

md5 mode—Message Digest 5 (MD5) mode used to authenticate packets during registration.

prefix-suffix—Wrapped registration information for authentication (for example, key registration information key) that calculates the message digest.

Note Cisco no longer recommends this method of authentication, but it is retained for backward compatibility.

hmac-md5—Hash-based Message Authentication Code (HMAC) MD5.

Note The HMAC-MD5 authentication algorithm or MD5 (prefix-suffix) authentication algorithm is mandatory for mobile-home authentication (MHAE), mobile-foreign authentication (MFAE), or foreign-home authentication (FHAE).


Defaults

No SA is specified for HAs.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2

The lower-address and upper-address arguments were added.

12.2(13)T

The hmac-md5 keyword was added.


Usage Guidelines

The SA consists of an entity address, SPI, key, replay protection method, authentication algorithm, and authentication algorithm mode (prefix-suffix).

The HA may have multiple SAs for each peer. The SPI specifies which SA to use for the peer and selects the specific security parameters to be used to authenticate the peer.

On an HA, the SA of the mobile host is mandatory for mobile host authentication and allows the HA to compute the MHAE for mobile host authentication. If desired, configure a foreign agent (FA) SA on your HA.

The mobile IP protocol automatically synchronizes the time stamp used by the mobile node (MN) in its registration requests. If the MN registration request time stamp is outside the HA permitted replay protection time interval, the HA will respond with the number of seconds by which the MN time stamp is off relative to the HA clock. This allows the MN to adjust its time stamp and use synchronized time stamps in subsequent registration attempts.

If you prefer that the MN first registration attempt always fall within the HA replay protection time interval, use Network Time Protocol (NTP) to synchronize the MN and HA.


Note NTP is not required for operation, but NTP can be used to synchronize time for all parties.


Examples

The following example shows the configuration of an SA for an HA with an IP address of 10.0.0.4:

ip mobile secure home-agent 10.0.0.4 spi 100 key hex ffffffff

Related Commands

Command
Description

ip mobile host

Configures the mobile host or mobile node group.

ip mobile proxy-host

Configures the proxy Mobile IP attributes.

ip mobile secure aaa-download

Configures the rate at which AAA security associations are downloaded.

ip mobile secure foreign-agent

Configures the mobility SAs for an FA.

ip mobile secure host

Configures the mobility SAs for a mobile host.

ip mobile secure mn-aaa

Specifies non-standard SPI values in the MN-AAA authentication extension that need to be accepted by the home agent or foreign agent.

ip mobile secure proxy-host

Configures the mobility SAs for a proxy host.

ip mobile secure visitor

Configures the mobility SAs for a visitor.

ntp server

Allows the system clock to be synchronized by a time server.

show ip mobile secure

Displays the mobility SAs for a mobile host, mobile visitor, FA, or HA.


ip mobile secure host

To specify the mobility security associations (SAs) for a mobile host, use the ip mobile secure host command in global configuration mode. To remove the mobility SAs, use the no form of this command.

ip mobile secure host {lower-address [upper-address] | nai nai-string} {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}] [skip-aaa-reauthentication]

no ip mobile secure host {lower-address [upper-address] | nai nai-string} {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}] [skip-aaa-reauthentication]

Syntax Description

lower-address

IP address of a host or lower range of IP address pool.

upper-address—(Optional) Upper range of IP address pool. If specified, SAs for multiple hosts are configured.

Note The upper-address value must be greater than the lower-address value.

nai

Network access identifier (NAI) of the mobile node (MN).

nai-string—NAI username or username@realm.

inbound-spi

Bidirectional 4-byte security parameter index (SPI) used for authenticating inbound registration packets.

spi-in—Index for inbound registration packets. The range is from 100 to ffffffff.

outbound-spi

SPI used for calculating the authenticator in outbound registration packets.

spi-out—Index for outbound registration packets. The range is from 100 to ffffffff.

spi

SPI authenticates a peer. The argument and keyword are as follows:

hex-value—SPI expressed as a hexadecimal number. The range is from 100 to ffffffff.

Note Cisco recommends that you use hexadecimal values instead of decimal values for interoperability.

decimal—Decimal SPI. The argument is as follows:

decimal-value—SPI expressed as a decimal number. The range is from 256 to 4294967295.

key

Security key. The arguments and keywords are as follows:

ascii string—Security key expressed as an ASCII string. A maximum of 32 characters is allowed. No spaces are allowed.

hex string—Security key expressed in hexadecimal digits. A maximum of 32 hex digits is allowed. The range is from 100 to ffffffff. No spaces are allowed.

replay timestamp

(Optional) Specifies the number of seconds that the router uses for replay protection.

seconds—Time, in seconds, that a router uses for replay protection. The range is from plus or minus 255. The default is plus or minus 7.

Note The registration packet is considered "not replayed" if the time stamp in the packet is within plus or minus the configured number of seconds of the router clock.

algorithm

(Optional) Algorithm used to authenticate messages during registration. The keywords are as follows:

md5 mode—Message Digest 5 (MD5) mode used to authenticate packets during registration.

prefix-suffix—Wrapped registration information for authentication (for example, key registration information key) that calculates the message digest.

Note Cisco no longer recommends this method of authentication, but it is retained for backward compatibility.

hmac-md5—Hash-based Message Authentication Code (HMAC) MD5.

Note The HMAC-MD5 authentication algorithm or MD5 (prefix-suffix) authentication algorithm is mandatory for mobile-home authentication (MHAE), mobile-foreign authentication (MFAE), or foreign-home authentication (FHAE).

skip-aaa- reauthentication

(Optional) When configured, the home agent does not send an access request for authentication for Mobile IP re-registration requests. When disabled, the home agent sends an access request for all Mobile IP registration requests.


Defaults

No SA is specified for mobile hosts.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2

The lower-address and upper-address arguments were added.

12.2(2)XC

The nai keyword was added.

12.2(13)T

The hmac-md5 keyword was added.

12.3(11)T

The skip-aaa-reauthentication command was added.


Usage Guidelines

The SA consists of an entity address, SPI, key, replay protection method, authentication algorithm, and authentication algorithm mode (prefix-suffix).

The SA of a visiting mobile host on the MFAE and the SA of the home agent (HA) on the FHAE are optional as long as they are not specified on the other entity. Multiple SAs for each entity can be configured.

The HMAC-MD5 authentication algorithm is mandatory for MHAE, MFAE, and FHAE.


Note NTP is not required for operation, but NTP can be used to synchronize time for all parties.


Examples

The following example shows the configuration of a host:

ip mobile secure host 10.0.0.4 spi 100 key hex 12345678123456781234567812345678

Related Commands

Command
Description

ip mobile host

Configures the mobile host or mobile node group.

ip mobile proxy-host

Configures the proxy Mobile IP attributes.

ip mobile secure aaa-download

Configures the rate at which AAA security associations are downloaded.

ip mobile secure foreign-agent

Configures the mobility SAs for an FA.

ip mobile secure home-agent

Configures the mobility SAs for an HA.

ip mobile secure mn-aaa

Specifies non-standard SPI values in the MN-AAA authentication extension that need to be accepted by the home agent or the foreign agent.

ip mobile secure proxy-host

Configures the mobility SAs for a proxy host.

ip mobile secure visitor

Configures the mobility SAs for a visitor.

ntp server

Allows the system clock to be synchronized by a time server.

show ip mobile secure

Displays the mobility SAs for a mobile host, mobile visitor, FA, or HA.


ip mobile secure mn-aaa

To specify non-standard security parameter index (SPI) values in the MN-AAA authentication extension that need to be accepted by the home agent or the foreign agent, use the ip mobile secure mn-aaa command in global configuration mode. To disable this functionality, use the no form of this command.

ip mobile secure mn-aaa spi {hex-value | decimal decimal-value} algorithm md5 mode ppp-chap-style

no ip mobile secure mn-aaa spi {hex-value | decimal decimal-value} algorithm md5 mode ppp-chap-style

Syntax Description

spi

Bidirectional security parameter index (SPI). The index can be a hexadecimal or decimal value. The arguments and keyword are as follows:

hex-value—SPI expressed in hexadecimal digits. The range is from 100 to ffffffff. No spaces are allowed. The maximum is 32 characters.

decimal decimal-value—SPI expressed as a decimal number. The range is from 256 to 4294967295. No spaces are allowed. The maximum is 32 characters.

algorithm md5 mode ppp-chap-style

Message Digest 5 (MD5) authentication algorithm used during authentication by the Challenge-Handshake Authentication Protocol (CHAP).


Defaults

The home agent or foreign agent only accept the standard SPI value in the MN-AAA authentication extension that specifes CHAP-style authentication using MD5. The standard value for the SPI is 2.

Command Modes

Global configuration

Command History

Release
Modification

12.2

This command was introduced.


Usage Guidelines

The SPI is the 4-byte index that selects the specific security parameters to be used to authenticate the peer. The security parameters consist of the authentication algorithm and mode.

A mobile node configured to be authenticated via an MN-AAA authentication extension is required to use an SPI value of 2 to indicate CHAP-style authentication using MD5 as specified by RFC 3012, Mobile IPv4 Challenge/Response Extensions.

Some network implementations need the flexibility to allow an SPI value other than 2 even though the mobile node is authenticated using CHAP. The ip mobile secure mn-aaa command maps new SPI values in the MN-AAA extension of the registration message to the SPI value pre-defined by RFC 3012. When a registration request arrives at the foreign agent or home agent with the MN-AAA extension containing an SPI value specified by the ip mobile secure mn-aaa command, the foreign agent or home agent will process it as if the value was 2 instead of rejecting the request.

Use this command with caution because it is non-standard behavior. For example, different vendors might use the same non-standard SPI to denote different authentication methods and this could affect interoperability. In general, Cisco recommends the use of standard SPI values to be used in the MN-AAA authentication extension by the mobile node.

Examples

In the following example, the foreign agent or home agent will process the registration request even though the CHAP SPI value is not 2:

ip mobile secure mn-aaa spi 1234 algorithm md5 mode ppp-chap-style

ip mobile secure proxy-host

To specify the mobility security associations (SAs) for a proxy host, use the ip mobile secure proxy-host command in global configuration mode. To remove the mobility SAs, use the no form of this command.

ip mobile secure proxy-host {lower-address [upper-address] | nai nai-string} {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}]

no ip mobile secure proxy-host {lower-address [upper-address] | nai nai-string} {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}]

Syntax Description

lower-address

IP address of a proxy host or lower range of IP address pool.

upper-address—(Optional) Upper range of IP address pool. If specified, SAs for multiple proxy hosts are configured.

Note The upper-address value must be greater than the lower-address value.

nai

Network access identifier (NAI) of the mobile node (MN).

nai-string—NAI username or username@realm.

inbound-spi

Bidirectional 4-byte security parameter index (SPI) used for authenticating inbound registration packets.

spi-in—Index for inbound registration packets. The range is from 100 to ffffffff.

outbound-spi

SPI used for calculating the authenticator in outbound registration packets.

spi-out—Index for outbound registration packets. The range is from 100 to ffffffff.

spi

SPI authenticates a peer. The argument and keyword are as follows:

hex-value—SPI expressed as a hexadecimal number. The range is from 100 to ffffffff.

Note Cisco recommends that you use hexadecimal values instead of decimal values for interoperability.

decimal—Decimal SPI. The argument is as follows:

decimal-value—SPI expressed as a decimal number. The range is from 256 to 4294967295.

key

Security key. The arguments and keywords are as follows:

ascii string—Security key expressed as an ASCII string. A maximum of 32 characters is allowed. No spaces are allowed.

hex string—Security key expressed in hexadecimal digits. A maximum of 32 hex digits is allowed. The range is from 100 to ffffffff. No spaces are allowed.

replay timestamp

(Optional) Specifies the number of seconds that the router uses for replay protection.

seconds—Time, in seconds, that a router uses for replay protection. The range is from plus or minus 255. The default is plus or minus 7.

Note The registration packet is considered "not replayed" if the time stamp in the packet is within plus or minus the configured number of seconds of the router clock.

algorithm

(Optional) Algorithm used to authenticate messages during registration. The keywords are as follows:

md5 mode—Message Digest 5 (MD5) mode used to authenticate packets during registration.

prefix-suffix—Wrapped registration information for authentication (for example, key registration information key) that calculates the message digest.

Note Cisco no longer recommends this method of authentication, but it is retained for backward compatibility.

hmac-md5—Hash-based Message Authentication Code (HMAC) MD5.

Note The HMAC-MD5 authentication algorithm or MD5 (prefix-suffix) authentication algorithm is mandatory for mobile-home authentication (MHAE), mobile-foreign authentication (MFAE), or foreign-home authentication (FHAE).


Defaults

No SA is specified for proxy hosts.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2

The lower-address and upper-address arguments were added.

12.2(2)XC

The nai keyword was added.

12.2(13)T

The hmac-md5 keyword was added.

12.3(4)T

The proxy-host keyword was added for Packet Data Serving Node (PDSN) platforms only.


Usage Guidelines

The SA consists of an entity address, SPI, key, replay protection method, authentication algorithm, and authentication algorithm mode (prefix-suffix).

The HMAC-MD5 authentication algorithm is mandatory for MHAE, MFAE, and FHAE.


Note The proxy-host keyword is available only on PDSN platforms that are running specific PDSN code images; consult Cisco Feature Navigator for your Cisco IOS software release.



Note NTP is not required for operation, but NTP can be used to synchronize time for all parties.


Examples

The following example shows the configuration of a proxy host:

ip mobile secure proxy-host 10.0.0.4 spi 100 key hex 12345678123456781234567812345678

Related Commands

Command
Description

ip mobile host

Configures the mobile host or mobile node group.

ip mobile proxy-host

Configures the proxy Mobile IP attributes.

ip mobile secure aaa-download

Configures the rate at which AAA security associations are downloaded.

ip mobile secure foreign-agent

Configures the mobility SAs for an FA.

ip mobile secure home-agent

Configures the mobility SAs for an HA.

ip mobile secure host

Configures the mobility SAs for a mobile host.

ip mobile secure mn-aaa

Specifies non-standard SPI values in the MN-AAA authentication extension that need to be accepted by the home agent or the foreign agent.

ip mobile secure visitor

Configures the mobility SAs for a visitor.

ntp server

Allows the system clock to be synchronized by a time server.

show ip mobile secure

Displays the mobility SAs for a mobile host, mobile visitor, FA, or HA.


ip mobile secure visitor

To specify the mobility security associations (SAs) for a visitor, use the ip mobile secure visitor command in global configuration mode. To remove the mobility security associations, use the no form of this command.

ip mobile secure visitor {lower-address [upper-address] | nai nai-string} {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}]

no ip mobile secure visitor {lower-address [upper-address] | nai nai-string} {inbound-spi spi-in outbound-spi spi-out | spi {hex-value | decimal decimal-value}} key {ascii string | hex string} [replay timestamp seconds] [algorithm {md5 mode prefix-suffix | hmac-md5}]

Syntax Description

lower-address

IP address of a visitor or lower range of IP address pool.

upper-address—(Optional) Upper range of IP address pool. If specified, SAs for multiple visitors are configured.

Note The upper-address value must be greater than the lower-address value.

nai

Network access identifier (NAI) of the mobile node (MN).

nai-string—NAI username or username@realm.

inbound-spi

Bidirectional 4-byte security parameter index (SPI) used for authenticating inbound registration packets.

spi-in—Index for inbound registration packets. The range is from 100 to ffffffff.

outbound-spi

SPI used for calculating the authenticator in outbound registration packets.

spi-out—Index for outbound registration packets. The range is from 100 to ffffffff.

spi

SPI authenticates a peer. The argument and keyword are as follows:

hex-value—SPI expressed as a hexadecimal number. The range is from 100 to ffffffff.

Note Cisco recommends that you use hexadecimal values instead of decimal values for interoperability.

decimal—Decimal SPI. The argument is as follows:

decimal-value—SPI expressed as a decimal number. The range is from 256 to 4294967295.

key

Security key. The arguments and keywords are as follows:

ascii string—Security key expressed as an ASCII string. A maximum of 32 characters is allowed. No spaces are allowed.

hex string—Security key expressed in hexadecimal digits. A maximum of 32 hex digits is allowed. The range is from 100 to ffffffff. No spaces are allowed.

replay timestamp

(Optional) Specifies the number of seconds that the router uses for replay protection.

seconds—Time, in seconds, that a router uses for replay protection. The range is from plus or minus 255. The default is plus or minus 7.

Note The registration packet is considered "not replayed" if the time stamp in the packet is within plus or minus the configured number of seconds of the router clock.

algorithm

(Optional) Algorithm used to authenticate messages during registration. The keywords are as follows:

md5 mode—Message Digest 5 (MD5) mode used to authenticate packets during registration.

prefix-suffix—Wrapped registration information for authentication (for example, key registration information key) that calculates the message digest.

Note Cisco no longer recommends this method of authentication, but it is retained for backward compatibility.

hmac-md5—Hash-based Message Authentication Code (HMAC) MD5.

Note The HMAC-MD5 authentication algorithm or MD5 (prefix-suffix) authentication algorithm is mandatory for mobile-home authentication (MHAE), mobile-foreign authentication (MFAE), or foreign-home authentication (FHAE).


Defaults

No SA is specified for visitors.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.2

The lower-address and upper-address arguments were added.

12.2(2)XC

The nai keyword was added.

12.2(13)T

The hmac-md5 keyword was added.


Usage Guidelines

The SA consists of an entity address, SPI, key, replay protection method, authentication algorithm, and authentication algorithm mode (prefix-suffix).

The SA of a visiting mobile host on the MFAE and the SA of the home agent (HA) on the FHAE are optional as long as they are not specified on the other entity. Multiple SAs for each entity can be configured.

The mobile IP protocol automatically synchronizes the time stamp used by the MN in its registration requests. If the MN registration request time stamp is outside the visitor permitted replay protection time interval, the visitor will respond with the number of secondsby which the MN time stamp is off relative to the visitor clock. This allows the MN to adjust its time stamp and use synchronized time stamps in subsequent registration attempts.

If you prefer that the MN first registration attempt always fall within the visitor replay protection time interval, use Network Time Protocol (NTP) to synchronize the MN and visitor.

The HMAC-MD5 authentication algorithm is mandatory for MHAE, MFAE, and FHAE.


Note NTP is not required for operation, but NTP can be used to synchronize time for all parties.


Examples

The following example shows the configuration of a visitor:

ip mobile secure visitor 10.0.0.4 spi 100 key hex 12345678123456781234567812345678

Related Commands

Command
Description

ip mobile host

Configures the mobile host or mobile node group.

ip mobile proxy-host

Configures the proxy Mobile IP attributes.

ip mobile secure aaa-download

Configures the rate at which AAA security associations are downloaded.

ip mobile secure foreign-agent

Configures the mobility SAs for an FA.

ip mobile secure home-agent

Configures the mobility SAs for an HA.

ip mobile secure host

Configures the mobility SAs for a mobile host.

ip mobile secure mn-aaa

Specifies non-standard SPI values in the MN-AAA authentication extension that need to be accepted by the home agent or the foreign agent.

ip mobile secure proxy-host

Configures the mobility SAs for a proxy host.

ntp server

Allows the system clock to be synchronized by a time server.

show ip mobile secure

Displays the mobility SAs for a mobile host, mobile visitor, FA, or HA.


ip mobile tunnel

To specify the settings of tunnels created by Mobile IP, use the ip mobile tunnel command in global configuration mode. To disable the setting of tunnels created by Mobile IP, use the no form of this command.

ip mobile tunnel {crypto map map-name | route-cache [cef] | path-mtu-discovery [age-timer {minutes | infinite}] | nat {inside | outside} | route-map map-tag}

no ip mobile tunnel {crypto map map-name | route-cache [cef] | path-mtu-discovery [age-timer {minutes | infinite}] | nat {inside | outside} | route-map map-tag}

Syntax DescriptionI

crypto map

Enables encryption or decryption on new tunnels. This keyword is only available on platforms running specific Packet Data Serving Node (PDSN) code images.

map-name

The name of the crypto map. This argument is available only on platforms running specific PDSN code images.

route-cache

Sets tunnels to fast-switching mode.

cef

Sets tunnels to Cisco Express Forwarding (CEF) switching mode if CEF is enabled on the router.

path-mtu-discovery

Specifies when the tunnel MTU should expire if set by Path MTU Discovery.

age-timer minutes

(Optional) Time interval in minutes after which the tunnel reestimates the path MTU.

infinite

(Optional) Turns off the age timer.

nat

Applies Network Address Translation (NAT) on the tunnel interface.

inside

Sets the dynamic tunnel as the inside interface for NAT.

outside

Sets the dynamic tunnel as the outside interface for NAT.

route-map map-tag

Defines a meaningful name for the route map.


Defaults

Disabled.

If enabled, default value for the minutes argument is 10 minutes.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.1(1)T

The nat, inside, and outside keywords were added.

12.2T

The cef keyword was added.

12.2(13)T

The route-map keyword and map-tag argument were added.

12.3(4)T

The crpto map keyword and map-name argument were added for PDSN platforms.


Usage Guidelines

Path MTU Discovery is used by end stations to find a packet size that does not need to be fragmented when being sent between the end stations. Tunnels must adjust their MTU to the smallest MTU interior to achieve this condition, as described in RFC 2003.

The discovered tunnel MTU should be aged out periodically to possibly recover from a case where suboptimum MTU existed at time of discovery. It is reset to the outgoing MTU of the interface.

The no ip mobile tunnel route-cache command disables fast switching and CEF switching (if CEF is enabled) on Mobile IP tunnels. The no ip mobile tunnel route-cache cef command disables CEF switching only.

CEF switching is currently not supported on a foreign agent when reverse tunneling is enabled. If reverse tunneling is enabled at the foreign agent, disable CEF on the foreign agent using the no ip cef global configuration command. If the foreign agent does not support reverse tunneling, there is no need to disable CEF at the global configuration level.

The crypto map map-name keyword and argument combination are available only on platforms running specific PDSN code images; consult Feature Navigator for your Cisco IOS software release.

Examples

The following example sets the discovered tunnel MTU to expire in 10 minutes (600 seconds):

ip mobile tunnel path-mtu-discovery age-timer 600

Related Commands

Command
Description

ip cef

Enables CEF on the RP card.

show ip mobile tunnel

Displays active tunnels.


ip mobile virtual-network

To define a virtual network, use the ip mobile virtual-network command in global configuration mode. To remove the virtual network, use the no form of this command.

ip mobile virtual-network net mask [address address]

no ip mobile virtual-network net mask [address address]

Syntax Description

net

Network associated with the IP address of the virtual network.

mask

Mask associated with the IP address of the virtual network.

address address

(Optional) IP address of a home agent on a virtual network.


Defaults

No home agent addresses are specified.

Command Modes

Global configuration

Command History

Release
Modification

12.0(1)T

This command was introduced.

12.0(2)T

The address keyword and address argument were added.


Usage Guidelines

This command inserts the virtual network into the routing table to allow mobile nodes to use the virtual network as their home network. The network is propagated when redistributed to other routing protocols.


Note You may need to include virtual networks when configuring the routing protocols. If this is the case, use the redistribute mobile router configuration command to redistribute routes from one routing domain to another.


Examples

The following example adds the virtual network 20.0.0.0 to the routing table and specifies that the home agent IP address is configured on the loopback interface for that virtual network:

interface ethernet 0
 ip address 1.0.0.1 255.0.0.0
 standby ip 1.0.0.10
 standby name SanJoseHA

interface loopback 0
 ip address 20.0.0.1 255.255.255.255

ip mobile home-agent
 ip mobile virtual-network 20.0.0.0 255.255.0.0 address 20.0.0.1
 ip mobile home-agent standby SanJoseHA virtual-network
 ip mobile secure home-agent 1.0.0.2 spi 100 hex 00112233445566778899001122334455

Related Commands

Command
Description

ip mobile host

Configures the mobile host or mobile node group.

redistribute mobile

Redistributes routes from one routing domain into another routing domain.


ip mobile vpn-realm

To define the virtual private network (VPN) realms to be used in home agent policy routing, use the ip mobile vpn-realm command in global configuration mode. To remove the VPN realms, use the no form of this command.

ip mobile vpn-realm realm-name {route-map-sequence sequence-number}

no ip mobile vpn-realm realm-name {route-map-sequence sequence-number}

Syntax Description

realm-name

Network access identifier (NAI) realm name.

route-map-sequence

Sequence of the route map.

sequence-number

Number that indicates the position a new route map is to have in the list of route maps already configured with the same name. If given with the no form of this command, it specifies the position of the route map that should be deleted. The sequence number range is from 0 to 65535.


Defaults

No default behavior or values.

Command Modes

Global configuration

Command History

Release
Modification

12.2(13)T

This command was introduced.


Usage Guidelines

The sequence-number argument must match that configured in the route-map sequence-number command.

Examples

The following example shows two realms configured on the router:

ip mobile vpn-realm company1.com route-map-sequence 20
ip mobile vpn-realm company2.com route-map-sequence 10

Related Commands

Command
Description

route map

Defines the conditions for redistributing routes from one routing protocol into another, or to enable policy routing.

show ip mobile vpn-realm

Displays VPN realms configured for Mobile IP.