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This chapter describes the Cisco IOS XR software commands used to configure and monitor Dynamic Host Configuration Protocol (DHCP).
For detailed information about DHCP concepts, configuration tasks, and examples, refer to the Cisco IOS XR IP Addresses and Services Configuration Guide for the Cisco XR 12000 Series Router.
To allow the server to delegate a valid client-suggested prefix in the solicit and request messages, use the allow-hint command in Dynamic Host Configuration Protocol (DHCP) IPv6 interface server configuration mode. To disable the delegation of a valid client-suggested prefix, use the no form of the command.
allow-hint
no allow-hint
This command has no keywords or arguments.
DHCPv6 service on an interface is disabled.
DHCP IPv6 interface server configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
The allow-hint command enables the server to delegate a client-suggested prefix in the solicit and request messages if the prefix in the associated local prefix pool is a valid prefix and it is not assigned to any other solicit and request messages. Otherwise, the hint is ignored, and a prefix is delegated from the free list in the pool.
Task ID |
Operations |
---|---|
ip-services |
read, write |
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# dhcp ipv6 interface pos 0/5/0/0 server RP/0/0/CPU0:router(config-dhcpv6-if)# allow-hint
To configure Dynamic Host Configuration Protocol (DHCP) IPv4 Relay to broadcast only BOOTREPLY packets if the DHCP IPv4 broadacst flag is set in the DHCP IPv4 header, use the broadcast-flag policy check command in DHCP IPv4 relay profile configuration submode . By default, the DHCP IPv4 Relay always broadcasts BOOTREPLY packets. To restore the default, use the no form of this command.
broadcast-flag policy{ check}
no broadcast-flag policy{ check}
check |
Checks the broadcast flag in packets. |
unicast-always |
Sets the broadcast-flag policy to unicast-always. |
Relay agent always broadcasts DHCP IPv4 packets to a client.
DHCP IPv4 relay profile configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
Release 4.2.0 |
This command was supported for BNG. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read, write |
RP/0/0/CPU0:router# config RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# profile client relay RP/0/0/CPU0:router(config-dhcpv4-relay-profile)# broadcast-flag policy check
Command |
Description |
---|---|
Enables DHCP for IPv4 and enters DHCP IPv4 configuration mode. |
|
Configures the DHCP relay agent to relay packets to a specific DHCP server. |
|
Configures a DHCP server to validate the relay agent information option in forwarded BOOTREPLY messages. |
|
Enables the system to insert a DHCP relay agent information option in forwarded BOOTREQUEST messages to a DHCP server. |
|
Configures the DHCP component to not drop BOOTREQUEST messages that have the relay information option set and the giaddr set to zero. |
|
Configures how a relay agent processes BOOTREQUEST messages that already contain a relay information option. |
To delete automatic client bindings from the Dynamic Host Configuration Protocol (DHCP) for IPv6 binding table, use the clear ipv6 dhcp binding command in EXEC mode.
clear dhcp ipv6 binding [ipv6-address]
ipv6-address |
(Optional) Address of a DHCP for an IPv6 client. This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons. |
No default behavior or values
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
The clear ipv6 dhcp binding command is used as a server function.
A binding table entry on the DHCP for IPv6 server is automatically:
If the clear ipv6 dhcp binding command is used with the optional ipv6-address argument specified, only the binding for the specified client is deleted. If the clear ipv6 dhcp binding command is used without the ipv6-address argument, then all automatic client bindings are deleted from the DHCP for IPv6 binding table.
Task ID |
Operations |
---|---|
ip-services |
execute |
The following example specifies DHCP for IPv6 binding database agent parameters:
RP/0/0/CPU0:router# clear dhcp ipv6 binding
Command |
Description |
---|---|
Displays the DHCP for the IPv6 binding database information. |
To configure a Dynamic Host Configuration Protocol (DHCP) for IPv6 binding database agent, use the database command in DHCP IPv6 configuration mode. To delete the database agent, use the no form of this command.
database agent-URL [ write-delay seconds ] [ timeout seconds ]
no database agent-URL
agent-URL |
A Flash, NVRAM, FTP, TFTP, or Remote Copy Protocol (RCP) uniform resource locator. |
write-delay seconds |
(Optional) How often (in seconds) DHCP for IPv6 sends database updates. The default is 300 seconds. The minimum write delay is 60 seconds. |
timeout seconds |
(Optional) Length of time, in seconds, the router waits for a database transfer. |
Write-delay default is 300 seconds.
Timeout default is 300 seconds.
DHCP IPv6 configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
The database command specifies DHCP for IPv6 binding database agent parameters. The user may configure multiple database agents.
The write-delay keyword specifies how often, in seconds, that DHCP sends database updates. By default, DHCP for IPv6 server waits 300 seconds before sending any database changes.
The timeout keyword specifies how long, in seconds, the router waits for a database transfer. Infinity is defined as 0 seconds, and transfers that exceed the timeout period are aborted. By default, the DHCP for IPv6 server waits 300 seconds before aborting a database transfer. When the system is going to reload, there is no transfer timeout so that the binding table can be stored completely.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following example specifies DHCP for IPv6 binding database agent parameters:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# dhcp ipv6 RP/0/0/CPU0:router(config-dhcpv6)# database tftp://10.0.0.1/dhcp-binding
Command |
Description |
---|---|
Enables Dynamic Host Configuration Protocol (DHCP) for IPv6 and enters DHCP IPv6 configuration mode. |
|
Enables DHCP for IPv6 on an interface. |
|
Displays the DHCP for the IPv6 binding database information. |
To specify a destination address to which client messages are forwarded and to enable Dynamic Host Configuration Protocol (DHCP) for IPv6 relay service on the interface, use the destination command in DHCP IPv6 interface relay configuration mode. To remove a relay destination on the interface or delete an output interface for a destination, use the no form of this command.
destination ipv6 address interface-path-id
no destination ipv6 address
Relay function is disabled and there is no relay destination on the interface.
DHCP IPv6 interface relay configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
Release 4.1.0 |
Support for DHCP IPv6 relay service. |
The destination command specifies a destination address to which client messages are forwarded and enables DHCP for IPv6 relay service on the interface. When relay service is enabled on an interface, a DHCP for IPv6 message received on that interface is forwarded to all configured relay destinations. The incoming DHCP for IPv6 message may have come from a client on that interface, or it may have been relayed by another relay agent.
The relay destination can be a unicast address of a server or another relay agent, or it may be a multicast address. There are the following two types of relay destination addresses:
A link-scoped unicast or multicast IPv6 address, for which a user must specify an output interface
A global unicast IPv6 address, for which a user can specify an output interface for this kind of address.
A global or site-scope multicast IPv6 address, for which a user can specify an output interface for this kind of address if 'mhost ipv6 default-interface' is specified.
If no output interface is configured for a destination, the output interface is determined by routing tables. In this case, it is recommended that a unicast or multicast routing protocol be running on the router.
Multiple destinations can be configured on one interface, and multiple output interfaces can be configured for one destination. When the relay agent relays messages to a multicast address, it sets the hop limit field in the IPv6 packet header to 32.
Unspecified, loopback, and node-local multicast addresses are not acceptable as the relay destination. If any one of them is configured, the message "Invalid destination address" is displayed.
Note that it is not necessary to enable the relay function on an interface for it to accept and forward an incoming relay reply message from servers. By default, the relay function is disabled, and there is no relay destination on an interface. The no form of the command removes a relay destination on an interface or deletes an output interface for a destination. If all relay destinations are removed, the relay service is disabled on the interface.
The DHCP for IPv6 client, server, and relay functions is mutually exclusive on an interface. When one of these functions is already enabled and a user tries to configure a different function on the same interface, one of the following messages is displayed: “Interface is in DHCP client mode,” “Interface is in DHCP server mode,” or “Interface is in DHCP relay mode.”
Task ID |
Operations |
---|---|
ip-services |
read, write |
RP/0/0/CPU0:router(config)# dhcp ipv6 RP/0/0/CPU0:router(config-dhcpv6)# interface tenGigE 0/5/0/0 relay RP/0/0/CPU0:router(config-dhcpv6-if)# destination 10:10::10
Command |
Description |
---|---|
Enables DHCP for IPv6 on an interface. |
To enable Dynamic Host Configuration Protocol (DHCP) for IPv4 and to enter DHCP IPv4 configuration mode, use the dhcp ipv4 command in Global Configuration mode. To disable DHCP for IPv4 and exit the DHCP IPv4 configuration mode, use the no form of this command.
dhcp ipv4
no dhcp ipv4
This command has no keywords or arguments.
None
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
Use the dhcp ipv4 command to enter DHCP IPv4 configuration mode.
Task ID |
Operations |
---|---|
ip-services |
read, write |
This example shows how to enable DHCP for IPv4:
RP/0/0/CPU0:router# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)#
To display DHCP client binding information, use the show dhcp ipv4 client command in EXEC mode.
show dhcp ipv4 client <interfaceName> [detail] [debug]
interfaceName |
Displays the DHCP IPv4 address of the specified interface. |
detail |
(Optional) Specifies detailed results. |
debug |
(Optional) Displays internal debugging information. |
No default behavior or values
EXEC mode
Release |
Modification |
---|---|
Release 5.2.0 |
This command was introduced. |
Use the show dhcp ipv4 client command to display the DHCP IPv4 for the specified client.
Task ID |
Operations |
---|---|
IP-Services |
read |
The following example shows how to display DHCP IPv4 binding information:
RP/0/0/CPU0:ios#show dhcp ipv4 client Mon May 6 16:35:32.581 UTC Interface name IP Address Binding State Lease Time Rem ---------------------- ------------ --------------- ---------------------- MgmtEth0_0_CPU0_0 192.168.190.130 BOUND 1688 secs (00:28:08) RP/0/0/CPU0:ios# RP/0/0/CPU0:ios#show dhcp ipv4 client binding ? MgmtEth Ethernet/IEEE 802.3 interface(s) detail Show detailed client binding information | Output Modifiers <cr> RP/0/0/CPU0:ios#show dhcp ipv4 client detail Mon May 6 16:35:56.579 UTC ----------------------------------------------------- Client Interface name : MgmtEth0_0_CPU0_0 Client Interface handle : 0x1280 Client Interface VRF name : default Client ChAddr : 000c.292f.950e Client ID : MgmtEth0_0_CPU0_0 Client State : BOUND Client IP Address (Dhcp) : 192.168.190.130 Client IP Address Mask : 255.255.255.0 Client Lease Time Allocated : 1800 secs (00:30:00) Client Lease Time Remaining : 1664 secs (00:27:44) Client Selected Server Addr : 192.168.190.254 ----------------------------------------------------- RP/0/0/CPU0:ios# RP/0/0/CPU0:ios#show dhcp ipv4 client binding detail ? MgmtEth Ethernet/IEEE 802.3 interface(s) debug Show detailed debug level client binding information | Output Modifiers <cr> RP/0/0/CPU0:ios#show dhcp ipv4 client detail debug Mon May 6 16:36:43.836 UTC ----------------------------------------------------- Client Interface name : MgmtEth0_0_CPU0_0 Client Interface handle : 0x1280 Client Interface VRF name : default Client ChAddr : 000c.292f.950e Client ID : MgmtEth0_0_CPU0_0 Client State : BOUND Client IP Address (Dhcp) : 192.168.190.130 Client IP Address Mask : 255.255.255.0 Client Lease Time Allocated : 1800 secs (00:30:00) Client Lease Time Remaining : 1617 secs (00:26:57) Client Selected Server Addr : 192.168.190.254 Client Interface VRF id : 0x60000000 Client Interface VRF Table id : 0xe0000000 Client XID : 0xa7f Client Timers Running : 0x2 (T1_RENEW_TIMER) Client Renew Time Allocated : 900 secs (00:15:00) Client Renew Time Adjusted : 900 secs (00:15:00) Client Rebind Time Allocated : 1575 secs (00:26:15) Client Rebind Time Adjusted : 1575 secs (00:26:15) Client Checkpoint object id : 0x80002fd8 Client IPv4 MA configured : TRUE ----------------------------------------------------- RP/0/0/CPU0:ios# RP/0/0/CPU0:ios#show dhcp ipv4 client mgmtEth 0/0/CPU0/0 Mon May 6 16:49:54.382 UTC Interface name IP Address Binding State Lease Time Rem ---------------------- ------------ --------------- ---------------------- MgmtEth0_0_CPU0_0 192.168.190.130 BOUND 1727 secs (00:28:47) RP/0/0/CPU0:ios#
To display DHCP client statistical information, use the show dhcp ipv4 client statistics command in EXEC mode.
show dhcp ipv4 client <interfaceName> statistics
interfaceName |
Displays the DHCP IPv4 statistical information of the specified interface. |
statistics |
Applies a statistics template and enable statistics collection. |
No default behavior or values
EXEC mode
Release |
Modification |
---|---|
Release 5.2.0 |
This command was introduced. |
Use the show dhcp ipv4 client statistics command to display the DHCP IPv4 statistical information for the specified client.
Task ID |
Operations |
---|---|
IP-Services |
read |
The following example shows how to display the DHCP IPv4 statistics information:
RP/0/0/CPU0:ios#show dhcp ipv4 client binding mgmtEth 0/0/CPU0/0 statistics Mon May 6 16:49:46.402 UTC ----------------------------------------------------- Client Interface name : MgmtEth0_0_CPU0_0 Client State : BOUND ----------------------------------------------------- TOTAL STATISTICS ----------------------------------------------------- DISCOVERS SENT : 1 OFFERS SENT : 1 OFFERS RECEIVED : 1 ACKS RECEIVED : 1 RELEASE SENT : 1 RESYNC SENT TO IM : 1 IPV4_MA CFG SENT : 1 IPV4_MA CFG SUCCESS : 1 INIT TIMER STARTED : x T1-RENEW TIMER STARTED : x T2_REBIND TIMER STARTED : x LEASE TIMER STARTED : x INIT TIMER STOPPED : x T1-RENEW TIMER STOPPED : x T2_REBIND TIMER STOPPED : x LEASE TIMER STOPPED : x ----------------------------------------------------- ERROR COUNTERS ----------------------------------------------------- OFFERS IGNORED : 1 ACK IGNORED : 1 DECLINE SENT : 1 NACK RECEIVED : 1 INVALID OFFERS RECEIVED : 1 INVALID ACKS RECEIVED : 1 IPV4_MA CFG FAILED : 0 IPV4_MA CFG FAILED REASON : "..." IM RESYNC ERROR REASON : "..."
To clear the DHCP client binding information configured on a given interface and set the binding information again, use the clear dhcp ipv4 client command in EXEC mode.
clear dhcp ipv4 client <interfaceName>
interfaceName |
Clears and restarts the DHCP IPv4 information of the specified interface. |
No default behavior or values
EXEC mode
Release |
Modification |
---|---|
Release 5.2.0 |
This command was introduced. |
Use the clear dhcp ipv4 client command to clear the DHCP client binding information for the specified interface.
Task ID |
Operations |
---|---|
IP-Services |
Execution |
The following example shows how to clear the DHCP client binding information:
RP/0/0/CPU0:ios#clear dhcp ipv4 client mgmtEth 0/0/CPU0/0 Fri Jun 6 08:24:14.558 UTC RP/0/0/CPU0:ios#show dhcp ipv4 client Fri Jun 6 08:24:17.377 UTC Interface name IP Address Binding State Lease Time Rem ---------------------- ------------ --------------- ---------------------- MgmtEth0/0/CPU0/0 11.11.11.5 BOUND 3598 secs (00:59:58) RP/0/0/CPU0:ios#show dhcp ipv4 client mgmtEth 0/0/CPU0/0 statistics Fri Jun 6 08:24:19.397 UTC Client Interface name : MgmtEth0/0/CPU0/0 ------------------------------------------------- CLIENT COUNTER(s) | VALUE ------------------------------------------------- Num discovers sent : 1 Num requests sent : 1 Num releases sent : 1 Num offers received : 1 Num acks received : 1 -------------------------------------------------
To clear DHCP client binding statistics information for a given interface, use the clear dhcp ipv4 client statistics command in EXEC mode.
clear dhcp ipv4 client <interfaceName> statistics
interfaceName |
DHCP IPv4 client enabled interface. |
statistics |
Clears DHCP IPv4 statistical information for the specified interface. |
No default behavior or values
Release |
Modification |
---|---|
Release 5.2.0 |
This command was introduced. |
Use the clear dhcp ipv4 client statistics command to clear the DHCP client binding statistics information for the specified interface.
Task ID |
Operations |
---|---|
IP-Services |
Execution |
The following example shows how to clear the DHCP client binding statistics information:
RP/0/0/CPU0:ios#show dhcp ipv4 client mgmtEth 0/0/CPU0/0 statistics Fri Jun 6 08:23:04.822 UTC Client Interface name : MgmtEth0/0/CPU0/0 ------------------------------------------------- CLIENT COUNTER(s) | VALUE ------------------------------------------------- Num discovers sent : 11 Num requests sent : 3 Num releases sent : 2 Num offers received : 3 Num acks received : 3 ------------------------------------------------- RP/0/0/CPU0:ios#clear dhcp ipv4 client mgmtEth 0/0/CPU0/0 statistics Fri Jun 6 08:23:11.852 UTC RP/0/0/CPU0:ios#show dhcp ipv4 client mgmtEth 0/0/CPU0/0 statistics Fri Jun 6 08:23:13.682 UTC Client Interface name : MgmtEth0/0/CPU0/0 ------------------------------------------------- CLIENT COUNTER(s) | VALUE ------------------------------------------------- ------------------------------------------------- RP/0/0/CPU0:ios#show dhcp ipv4 client Fri Jun 6 08:23:16.862 UTC Interface name IP Address Binding State Lease Time Rem ---------------------- ------------ --------------- ---------------------- MgmtEth0/0/CPU0/0 11.11.11.5 BOUND 3562 secs (00:59:22)
Command | Description |
| Displays the statistics of the DHCP client. |
| Displays DHCP IPv4 client information. |
To retrieve the DHCP client show tech support information, use the show tech dhcp ipv4 client command in EXEC mode.
show tech-support dhcp ipv4 client <show-tech-options>
show-tech-options |
Displays the DHCP IPv4 client show tech-support options. |
No default behavior or values
Release |
Modification |
---|---|
Release 5.2.0 |
This command was introduced. |
Use the show tech-support dhcp ipv4 client command to retrieve the DHCP show-tech options for the specified interface.
Task ID |
Operations |
---|---|
IP-Services |
Execution |
The following example shows how to clear the DHCP client binding statistics information:
RP/0/0/CPU0:ios#show tech-support dhcp ipv4 client ? file Specify a valid file name (e.g. disk0:tmp.log)(cisco-support) terminal Send output to terminal(cisco-support) RP/0/0/CPU0:ios#show tech-support dhcp ipv4 client file ? WORD Send to file bootflash: Send to bootflash: file system(cisco-support) disk0: Send to disk0: file system(cisco-support) disk0a: Send to disk0a: file system(cisco-support) disk1: Send to disk1: file system(cisco-support) disk1a: Send to disk1a: file system(cisco-support) ftp: Send to ftp: file system(cisco-support) nvram: Send to nvram: file system(cisco-support) rcp: Send to rcp: file system(cisco-support) tftp: Send to tftp: file system(cisco-support) RP/0/0/CPU0:ios#show tech-support dhcp ipv4 client file disk0? WORD disk0: disk0a: RP/0/0/CPU0:ios#show tech-support dhcp ipv4 client file disk0:/dhcpv4-client-showtech.tgz Fri Jun 6 08:25:24.793 UTC RP/0/0/CPU0:ios#dir disk0: Fri Jun 6 08:25:47.321 UTC Directory of disk0: 2 drwx 1024 Thu Mar 13 06:12:03 2014 .boot … 3 -rw- 83337 Fri Jun 6 08:25:26 2014 dhcpv4-client-showtech.tgz 1911537664 bytes total (1838081024 bytes free) RP/0/0/CPU0:ios#
Command | Description |
| Displays DHCP IPv4 client information. |
| Displays the statistics of the DHCP client. |
To enable Dynamic Host Configuration Protocol (DHCP) for IPv6 and to enter DHCP IPv6 configuration mode, use the dhcp ipv6 command in Global Configuration mode. To disable the DHCP for IPv6, use the no form of this command.
dhcp ipv6
no dhcp ipv6
This command has no keywords or arguments.
Release |
Modification |
---|---|
Release 3.6.0 |
This command was introduced. |
Release 4.3.0 |
This command was supported for BNG. |
Task ID |
Operations |
---|---|
ip-services |
read, write |
This example shows how to enable DHCP for IPv6:
RP/0/0/CPU0:router(config)# dhcp ipv6 RP/0/0/CPU0:router(config-dhcpv6)#
Command |
Description |
---|---|
Configures a Dynamic Host Configuration Protocol (DHCP) for IPv6 binding database agent. |
|
Specifies an administrative distance for Dynamic Host Configuration Protocol (DHCP) for IPv6 Prefix Delegation. |
|
Configures a Dynamic Host Configuration Protocol (DHCP) for the IPv6 server configuration information pool and enters DHCP for IPv6 pool configuration mode. |
To specify an administrative distance for Dynamic Host Configuration Protocol (DHCP) for IPv6 Prefix Delegation, use the distance command in DHCP IPv6 configuration mode. To delete an administrative distance, use the no form of this command.
distance administrative distance
no distance administrative distance
administrative distanc e |
User defined distance. The range is 1 to 255. |
administrative distance : 1
DHCP IPv6 configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following is an example of setting the DHCP administrative distance to 200 using the distance command:
RP/0/0/CPU0:router(config)# dhcp ipv6 RP/0/0/CPU0:router(config-dhcpv6)# distance 200
Command |
Description |
---|---|
Enables Dynamic Host Configuration Protocol (DHCP) for IPv6 and enters DHCP IPv6 configuration mode. |
To specify the Domain Name System (DNS) IPv6 servers available to a Dynamic Host Configuration Protocol (DHCP) for IPv6 client, use the dns-server command in an appropriate configuration mode. To remove the DNS server list, use the no form of this command.
dns-server ipv6-address
no dns-server ipv6-address
ipv6-address |
IPv6 address of a DNS server. This argument must be in the form documented in RFC 2373, where the address is specified in hexadecimal using 16-bit values between colons. |
When a DHCP for IPv6 pool is first created, no DNS IPv6 servers are configured.
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
Multiple Domain Name System (DNS) server addresses can be configured by issuing this command multiple times. New addresses do not overwrite old addresses.
Task ID |
Operations |
---|---|
ip-services |
read, write |
RP/0/0/CPU0:router(config)# dhcp ipv6 pool pool1 RP/0/0/CPU0:router(config-dhcpv6-pool)# dns-server 10:10::10
To configure a domain name for a Dynamic Host Configuration Protocol (DHCP) for IPv6 client, use the domain-name command in an appropriate configuration mode. To remove the domain name, use the no form of this command.
domain-name domain
no domain-name
domain |
Specifies the domain name string to be used by the client. |
When a DHCP for IPv6 pool is first created, no domain name for clients is configured.
DHCP IPv6 pool configuration
Multiple Domain Name System (DNS) domain names can be configured by issuing the domain-name command multiple times. The new domain name does not overwrite existing domain names.
The domain name is defined in DHCP IPv6 server profile and DHCP IPv6 server profile class configuration. If the same parameters are defined in the class scope, then the values defined in the class scope takes precedence.
Task ID |
Operations |
---|---|
ip-services |
read, write |
RP/0/0/CPU0:router(config)# dhcp ipv6 pool pool1 RP/0/0/CPU0:router(config-dhcpv6-pool)# domain-name howie.com
To define the Dynamic Host Configuration Protocol (DHCP) the unique identification (DUID) on a specified device, use the duid command in DHCP IPv6 configuration mode. To delete an administrative distance, use the no form of this command.
duid duid name
no duid duid name
duid name |
IPv6 DHCP unique identifier (DUID) in hex format. The length of DUID word should be even. |
DUID-LL as defined in Section 9.4 of RFC3315
DHCP IPv6 configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
Use the duid command to configure the DHCP unique identifier on a specified device. Use the no form of this command to restore the default.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following is an example of how to create an IPv6 DHCP unique identifier (DUID) of 0002000000090CC084D303000912 using the duid command:
RP/0/0/CPU0:router(config)# dhcp ipv6 RP/0/0/CPU0:router(config-dhcpv6)# duid 0002000000090CC084D303000912
Command |
Description |
---|---|
Enables Dynamic Host Configuration Protocol (DHCP) for IPv6 and enters DHCP IPv6 configuration mode. |
To configure how Dynamic Host Configuration Protocol (DHCP) IPv4 Relay processes BOOTREQUEST packets that already contain a nonzero giaddr attribute, use the giaddr policy command in DHCP IPv4 profile relay configuration submode. To restore the default giaddr policy, use the no form of this command.
giaddr policy { replace | drop }
no giaddr policy { replace | drop }
replace |
Replaces the existing giaddr value with a value that it generates. |
drop |
Drops the packet that has an existing nonzero giaddr value. |
DHCP IPv4 relay retains the existing nonzero giaddr value in the DHCP IPv4 packet received from a client value.
DHCP IPv4 profile relay configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
The giaddr policy command affects only the packets that are received from a DHCP IPv4 client that have a nonzero giaddr attribute.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following example shows how to use the giaddr policy command:
RP/0/0/CPU0:router# config RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# profile client relay RP/0/0/CPU0:router(config-dhcpv4-relay-profile)# giaddr policy drop
Command |
Description |
---|---|
Enables DHCP for IPv4 and enters DHCP IPv4 configuration mode. |
|
Configures the DHCP relay agent to relay packets to a specific DHCP Server. |
|
Specifies a relay profile on an interface. |
|
Configures a DHCP server to validate the relay agent information option in forwarded BOOTREPLY messages. |
|
Enables the system to insert a DHCP relay agent information option in forwarded BOOTREQUEST messages to a DHCP server. |
|
Configures the DHCP component to not drop BOOTREQUEST messages that have the relay information option set and the giaddr set to zero. |
|
Configures how a relay agent processes BOOTREQUEST messages that already contain a relay information option. |
To configure the Dynamic Host Configuration Protocol (DHCP) IPv4 relay agent to relay DHCP packets to a specific DHCP server, use the helper-address command in an appropriate configuration mode. Use the no form of this command to clear the address.
helper-address [ vrf vrf-name ] [ address] [ giaddr gateway-address]
no helper-address [ vrf vrf-name ] [ address] [ giaddr gateway-address]
vrf-name |
(Optional) Specifies the name of a particular VRF. |
address |
IPv4 and Pv6 address in four part, dotted decimal format. |
giaddr gateway-address |
(Optional) Specifies the gateway address to use in packets relayed to server. This keyword is applicable for IPv4 helper address. |
Helper address is not configured.
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
A maximum of upto eight helper addresses can be configured.
Task ID |
Operations |
---|---|
ip-services |
read, write |
Command |
Description |
---|---|
Enables Dynamic Host Configuration Protocol (DHCP) for IPv4 and enters DHCP IPv4 configuration mode. |
|
Specifies a relay profile on an interface. |
|
Configures a DHCP server to validate the relay agent information option in forwarded BOOTREPLY messages. |
|
Enables the system to insert a DHCP relay agent information option in forwarded BOOTREQUEST messages to a DHCP server. |
|
Configures the DHCP component to not drop BOOTREQUEST messages that have the relay information option set and the giaddr set to zero. |
|
Configures how a relay agent processes BOOTREQUEST messages that already contain a relay information option. |
To enable Dynamic Host Configuration Protocol (DHCP) for IPv4 on an interface, use the interface command in the appropriate configuration mode. To disable DHCPv4 on an interface, use the no form of the command.
interface type interface-path-id { server | relay }
interface type interface-path-id { base | | relay | server }
type
|
Interface type. For more information, use the question mark (?) online help function. |
||
interface-path-id
|
Physical interface or virtual interface.
For more information about the syntax for the router, use the question mark (?) online help function. |
||
server
|
Enables service on the specified interface using the pool for prefix delegation. |
||
relay |
Attaches a relay profile for the specified interface. |
None
DHCP IPv6 configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
Task ID |
Operations |
---|---|
ip-services |
read, write |
To configure a relay profile on an interface, use the interface (relay profile) command in Dynamic Host Configuration Protocol (DHCP) IPv4 configuration mode. To disable this feature, use the no form of the command.
interface interface-type interface-path-id { none | relay }
no interface interface-type interface-path-id { none | relay }
interface-type |
Interface type. For more information, use the question mark (?) online help function. |
interface-path-id |
Either a physical interface instance or a virtual interface instance. |
none |
Disables DHCP at the specified interface. |
relay |
Specifies a relay profile for the interface. |
DHCP IPv4 configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read, write |
RP/0/0/CPU0:router# config RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# interface pos 0/1/4/1 RP/0/0/CPU0:router(config-dhcpv4)# interface pos 0/1/4/1 relay profile client
Command |
Description |
---|---|
Configures a relay agent to only broadcast DHCP IPv4 BOOTREPLY messages to a client, if the DHCP IPv4 broadcast flag is set in the DHCP IPv4 header. |
|
Enables Dynamic Host Configuration Protocol (DHCP) for IPv4 and enters DHCP IPv4 configuration mode. |
|
Configures how a relay agent processes BOOTREQUEST messages that already contain a nonzero giaddr attribute. |
|
Configures the DHCP relay agent to relay packets to a specific DHCP Server. |
|
Configures a DHCP server to validate the relay agent information option in forwarded BOOTREPLY messages. |
|
Enables the system to insert a DHCP relay agent information option in forwarded BOOTREQUEST messages to a DHCP server. |
|
Configures the DHCP component to not drop BOOTREQUEST messages that have the relay information option set and the giaddr set to zero. |
|
Configures how a relay agent processes BOOTREQUEST messages that already contain a relay information option. |
|
Specifies a relay profile on a VRF. |
To specify a manually configured numeric prefix to be delegated to a specified client (and optionally a specified identity association for prefix delegation [IAPD] for that client), use the pd command in Dynamic Host Configuration Protocol (DHCP) IPv6 pool configuration mode. To remove the prefix, use the no form of this command.
pd ipv6 prefix prefix-length client -DUID [iaid iaid][ lifetime]
ipv6-prefix |
(Optional) Specified IPv6 prefix. This argument must be in the form documented in RFC 2373, where the address is specified in hexadecimal using 16-bit values between colons |
/prefix-length |
Length of the IPv6 prefix. A decimal value that indicates how many of the high-order contiguous bits of the address comprise the prefix (the network portion of the address). |
client-DUID |
The DHCP unique identifier (DUID) of the client to which the prefix is delegated. |
iaid iaid |
(Optional) Identity association identifier (IAID), which uniquely identifies an IAPD on the client. |
lifetime |
(Optional) Sets a length of time during which the requesting router is allowed to use the prefix. The following values can be used:
|
No manually configured prefix delegations exist.
DHCP IPv6 pool configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following is an example of the pd command in DHCP IPv6 pool configuration mode:
RP/0/0/CPU0:router(config)# dhcp ipv6 pool pool1 RP/0/0/CPU0:router(config-dhcpv6-pool)# pd 2001:420:10::/48 0002000000090CC084D303000912
Command |
Description |
---|---|
Configures a Dynamic Host Configuration Protocol (DHCP) for the IPv6 server configuration information pool and enters DHCP for IPv6 pool configuration mode. |
To allow the identification of a client based on client connection to a specific interface, use the pd command in DHCP IPv6 interface server configuration mode. To remove the prefix, use the no form of this command.
pd ipv6 prefix prefix -length[ lifetime]
no pd ipv6 prefix prefix -length[ lifetime]
ipv6-prefix |
(Optional) Specified IPv6 prefix. This argument must be in the form documented in RFC 2373, where the address is specified in hexadecimal using 16-bit values between colons |
/prefix-length |
Length of the IPv6 prefix. A decimal value that indicates how many of the high-order contiguous bits of the address comprise the prefix (the network portion of the address). |
lifetime |
(Optional) Sets a length of time over which the requesting router is allowed to use the prefix. The following values can be used:
|
No manually configured prefix delegations exist.
DHCP IPv6 interface server configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read, write |
RP/0/0/CPU0:router(config)# dhcp ipv6 RP/0/0/CPU0:router(config-dhcpv6)# pool pool1 RP/0/0/CPU0:router(config-dhcpv6-pool)# exit RP/0/0/CPU0:router(config-dhcpv6)# interface POS 0/5/0/0 server RP/0/0/CPU0:router(config-dhcpv6-if)# pd 2001:420:10::/48 RP/0/0/CPU0:router(config-dhcpv6-if)# pool pool1
Command |
Description |
---|---|
Enables DHCP for IPv6 on an interface. |
To configure a Dynamic Host Configuration Protocol (DHCP) for the IPv6 server configuration information pool and enter DHCP for IPv6 pool configuration mode, use the pool command in either DHCP IPv6 configuration mode or DHCP IPv6 interface relay configuration mode. To delete a DHCP for IPv6 pool, use the no form of this command.
pool poolname
no pool poolname
poolname |
User-defined name for the local prefix pool. The pool name can be a symbolic string (such as “Engineering”) or an integer (such as 0). |
No DHCP for IPv6 pools are configured.
DHCP IPv4
IPv6 configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
Use the pool command to create a DHCP for IPv6 server configuration information pool. When the pool command is enabled, the configuration mode changes to DHCP for IPv6 pool configuration mode. In this mode, the administrator can configure pool parameters, such as prefixes to be delegated and Domain Name System (DNS) servers.
Once the DHCP for IPv6 configuration information pool has been created, use the server command to associate the pool with a server on an interface.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following example show how to enter pool configuration mode using the pool command:
RP/0/0/CPU0:router(config)# dhcp ipv6 RP/0/0/CPU0:router(config-dhcpv6)# pool pool1 RP/0/0/CPU0:router(config-dhcpv6-pool)#
Command |
Description |
---|---|
Enables Dynamic Host Configuration Protocol (DHCP) for IPv6 and enters DHCP IPv6 configuration mode. |
|
Displays DHCP for IPv6 configuration information pool information. |
To configure the preference value, use the preference command in DHCP IPv6 interface server configuration mode. To disable the preference value, use the no form of the command.
preference preference value
no preference
preference value |
Preference value carried in the preference option in the advertise message sent by the server. The range is from 0 to 255. |
The preference value defaults to zero.
DHCP IPv6 interface server configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
The preference command configures a preference value. If the preference value is configured and it is not 0, the server adds a preference option to carry the preference value for the advertise message to a client to affect the selection of a server by client.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following is an example of the preference command:
RP/0/0/CPU0:router(config)# dhcp ipv6 RP/0/0/CPU0:router(config-dhcpv6)# interface pos 0/5/0/0 server RP/0/0/CPU0:router(config-dhcpv6-if)# preference 1
To configure a relay profile for the Dynamic Host Configuration Protocol (DHCP) IPv4 component and to enter the profile relay mode, use the profile relay command in DHCP IPv4 configuration mode. To disable this feature and exit the profile relay mode, use the no form of this command.
profile profile name relay
no profile profile name relay
profile name |
Name that uniquely identifies the relay profile. |
DHCP IPv4 configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced . |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following example shows how to use the profile relay command:
RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# profile client relay
Command |
Description |
---|---|
Configures a relay agent to only broadcast DHCP IPv4 BOOTREPLY messages to a client, if the DHCP IPv4 broadcast flag is set in the DHCP IPv4 header. |
|
Enables DHCP for IPv4 and enters DHCP IPv4 configuration mode. |
|
Configures how a relay agent processes BOOTREQUEST messages that already contain a nonzero giaddr attribute. |
|
Configures the DHCP relay agent to relay packets to a specific DHCP Server. |
|
Specifies a relay profile on an interface. |
|
Configures a DHCP server to validate the relay agent information option in forwarded BOOTREPLY messages. |
|
Enables the system to insert a DHCP relay agent information option in forwarded BOOTREQUEST messages to a DHCP server. |
|
Configures the DHCP component to not drop BOOTREQUEST messages that have the relay information option set and the giaddr set to zero. |
|
Configures how a relay agent processes BOOTREQUEST messages that already contain a relay information option. |
|
Specifies a relay profile on a VRF. |
To enable clients that specify the Rapid Commit option in their Solicit messages to receive immediate address assignment Reply messages, use the rapid-commit command in Dynamic Host Configuration Protocol (DHCP) IPv6 interface server mode. To disable DHCP for IPv6 service on an interface, use the no form of this command.
rapid-commit
no rapid-commit
Rapid commit is disabled.
DHCP IPv6 interface server configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
The rapid-commit command enables or disables rapid commit. If enabled, the DHCPv6 server uses the two-message exchange for prefix delegation and other configuration. If a client has included a rapid commit option in the solicit message and rapid-commit is enabled for the server, the server responds to the solicit message with a reply message. If rapid-commit is not enabled, then normal four-message exchange is done even if the clients specifies the rapid commit option.
Task ID |
Operations |
---|---|
ip-services |
read, write |
RP/0/0/CPU0:router(config)# dhcp ipv6 RP/0/0/CPU0:router(config-dhcpv6)# interface pos 0/5/0/0 server RP/0/0/CPU0:router(config-dhcpv6-if)# rapid-commit
Command |
Description |
---|---|
Enables DHCP for IPv6 on an interface. |
To configure a Dynamic Host Configuration Protocol (DHCP) IPv4 Relay to validate the relay agent information option in forwarded BOOTREPLY messages, use the relay information check command in DHCP IPv4 relay profile configuration submode. To disable this feature, use the no form of this command.
relay information check
no relay information check
This command has no keywords or arguments.
DHCP validates the relay agent information option.
DHCP IPv4 relay profile configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read, write |
basic-services |
read, write |
This example shows how to use the relay information check command:
RP/0/0/CPU0:router#config RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# profile client relay RP/0/0/CPU0:router(config-dhcpv4-relay-profile)# relay information check
Command |
Description |
---|---|
Enables DHCP for IPv4 and enters DHCP IPv4 configuration mode. |
|
Configures the DHCP relay agent to relay packets to a specific DHCP Server. |
|
Enables the system to insert a DHCP relay agent information option in forwarded BOOTREQUEST messages to a DHCP server. |
|
Configures the DHCP component to not drop BOOTREQUEST messages that have the relay information option set and the giaddr set to zero. |
To configure Dynamic Host Configuration Protocol (DHCP) IPv4 relay or DHCP snooping Relay to insert relay agent information option in forwarded BOOTREQUEST messages to a DHCP server, use the relay information option command in DHCP IPv4 relay profile relay configuration or DHCP IPv4 profile snoop submode. To disable inserting relay information into forwarded BOOTREQUEST messages, use the no form of this command.
relay information option
no relay information option
This command has no keywords or arguments.
None
DHCP IPv4
relay
profile
relay
configuration
DHCP IPv4 profile snoop configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
The relay information option command automatically adds the circuit identifier suboption and the remote ID suboption to the DHCP relay agent information option.
The relay information option command enables a DHCP server to identify the user (for example, cable access router) sending the request and initiate appropriate action based on this information. By default, DHCP does not insert relay information.
If the information option command is enabled, DHCP snooping mode does not set the giaddr field in the DHCP packet.
The upstream DHCP server or DHCP relay interface must be configured to accept this type of packet using the relay information option allow-untrusted configuration. This configuration prevents the server or relay from dropping the DHCP message.
Task ID |
Operations |
---|---|
ip-services |
read, write |
basic-services |
read, write |
This example shows how to use the relay information option command:
RP/0/0/CPU0:router# config RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# profile client relay RP/0/0/CPU0:router(config-dhcpv4-relay-profile)# relay information option
Command |
Description |
---|---|
Enables DHCP for IPv4 and enters DHCP IPv4 configuration mode. |
|
Configures the DHCP relay agent to relay packets to a specific DHCP Server. |
|
Configures a DHCP server to validate the relay agent information option in forwarded BOOTREPLY messages. |
|
Configures the DHCP component to not drop BOOTREQUEST messages that have the relay information option set and the giaddr set to zero. |
To configure the Dynamic Host Configuration Protocol (DHCP) IPv4 relay or DHCP snooping Relay not to drop discard BOOTREQUEST packets that have the relay information option set and the giaddr set to zero, use the relay information option allow-untrusted command in DHCP IPv4 relay profile configuration submode or DHCP IPv4 profile snoop configuration submode. To restore the default behavior, which is to discard the BOOTREQUEST packets that have the relay information option and set the giaddr set to zero, use the no form of this command.
relay information option allow-untrusted
no relay information option allow-untrusted
This command has no keywords or arguments.
The packet is dropped if the relay information is set and the giaddr is set to zero.
DHCP IPv4
relay
profile
relay
configuration
DHCP IPv4 profile snoop configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
According to RFC 3046, relay agents (and servers) receiving a DHCP packet from an untrusted circuit with giaddr set to zero but with a relay agent information option already present in the packet shall discard the packet and increment an error count. This configuration prevents the server or relay from dropping the DHCP message.
Task ID |
Operations |
---|---|
ip-services |
read, write |
basic-services |
read, write |
This example shows how to use the relay information option allow-untrusted command:
RP/0/0/CPU0:router# config RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# profile client relay RP/0/0/CPU0:router(config-dhcpv4-relay-profile)# relay information option allow-untrusted
Command |
Description |
---|---|
Enables DHCP for IPv4 and enters DHCP IPv4 configuration mode. |
|
Configures the DHCP relay agent to relay packets to a specific DHCP Server. |
|
Configures a DHCP server to validate the relay agent information option in forwarded BOOTREPLY messages. |
|
Enables the system to insert a DHCP relay agent information option in forwarded BOOTREQUEST messages to a DHCP server. |
To configure how the Dynamic Host Configuration Protocol (DHCP) IPv4 relay processes BOOTREQUEST packets that already contain a relay information option, use the relay information policy command in DHCP IPv4 relay profile configuration submode. To restore the default relay information policy, use the no form of this command.
relay information policy { drop | keep }
no relay information policy { drop | keep }
drop |
Directs the DHCP IPv4 Relay to discard BOOTREQUEST packets with the existing relay information option. |
keep |
Directs the DHCP IPv4 Relay not to discard a BOOTREQUEST packet that is received with an existing relay information option and to keep the existing relay information option value. |
The DHCP IPv4 Relay does not discard a BOOTREQUEST packet that has an existing relay information option. The option and the existing relay information option value is replaced.
DHCP IPv4 relay profile configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
Task ID |
Operations |
---|---|
ip-services |
read, write |
basic-services |
read, write |
This is sample output from executing the relay information policy command:
RP/0/0/CPU0:router# config RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# profile client relay RP/0/0/CPU0:router(config-dhcpv4-relay-profile)# relay information policy keep
Command |
Description |
---|---|
Enables DHCP for IPv4 and enters DHCP IPv4 configuration mode. |
|
Configures the DHCP relay agent to relay packets to a specific DHCP Server. |
|
Configures a DHCP server to validate the relay agent information option in forwarded BOOTREPLY messages. |
|
Enables the system to insert a DHCP relay agent information option in forwarded BOOTREQUEST messages to a DHCP server. |
|
Configures the DHCP component to not drop BOOTREQUEST messages that have the relay information option set and the giaddr set to zero. |
|
Specifies a relay profile on an interface. |
To allow DHCP to add an ARP cache entry when DHCP assigns an IP address to a client in IP subscriber sessions, use the secure-arp command in DHCP IPv4 profile proxy configuration or DHCP IPv4 server profile mode. To disallow DHCP to add an ARP cache entry when DHCP assigns an IP address to a client, use the no form of this command.
secure-arp
no secure-arp
This command has no keywords or arguments.
By default, secure ARP support is disabled.
DHCP IPv4 proxy profile configuration
DHCP IPv4 Server Profile
Release | Modification |
---|---|
This command was introduced. |
In standalone DHCP sessions, the DHCP server adds an ARP entry when it assigns an IP address to a client. However, for IP subscriber sessions, DHCP server does not add an ARP entry. Although ARP establishes correspondences between network addresses, an untrusted device can spoof IP an address not assigned to it posing a security threat for IP subscriber sessions.
Secure ARP allows DHCP to add an ARP cache entry when DHCP assigns an IP address to a client in IP subscriber sessions. This is to prevent untrusted devices from spoofing IP addresses not assigned to them. Secure ARP is disabled by default.
Task ID | Operation |
---|---|
ip-services |
read, write |
This examples shows how to allow DHCP to add an ARP cache entry when DHCP assigns an IP address to a client using the secure-arp command in DHCP IPv4 server profile configuration:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# profile profile1 server RP/0/0/CPU0:router(config-dhcpv4-server-profile)# secure-arp RP/0/0/CPU0:router(config-dhcpv4-server-profile)#
To display Dynamic Host Configuration Protocol (DHCP) relay agent status, use the show dhcp ipv4 relay profile command in EXEC mode.
show dhcp ipv4 relay profile
This command has no keywords or arguments.
No default behavior or values
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
This command displays the relay profiles created for DHCP IPv4.
Task ID |
Operations |
---|---|
ip-services |
read |
The following is sample output from the show dhcp ipv4 relay profile command:
RP/0/0/CPU0:router# show dhcp ipv4 relay profile
DHCP IPv4 Relay Profiles
--------------------------
r1
r2
Command |
Description |
---|---|
Displays Dynamic Host Configuration Protocol (DHCP) relay agent status, specific to a relay profile. |
To display Dynamic Host Configuration Protocol (DHCP) relay agent status, specific to a relay profile, use the show dhcp ipv4 relay profile name command in EXEC mode.
show dhcp ipv4 relay profile [ name]
name |
(Optional) Name that uniquely identifies the relay profile. |
If name is not specified, displays a list of configured DHCP profile names.
No default behavior or values
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read |
The following is sample output from the show dhcp ipv4 relay profile name command:
RP/0/0/CPU0:router# show dhcp ipv4 relay profile name r1 DHCP IPv4 Relay Profile r1: Helper Addresses: 10.10.10.1, vrf default Information Option: Disabled Information Option Allow Untrusted: Disabled Information Option Policy: Replace Information Option Check: Disabled Giaddr Policy: Keep Broadcast-flag Policy: Ignore VRF References: default Interface References: FINT0_0_CPU0 MgmtEth0_0_CPU0_0
To display the Dynamic Host Configuration Protocol (DHCP) IPv4 relay agent packet statistics information for VPN routing and forwarding (VRF) instances, use the show dhcp ipv4 relay statistics command in EXEC mode.
show dhcp [ vrf { vrf-name | default } ] ipv4 relay statistics
vrf vrf-name |
(Optional) Name that uniquely identifies the VRF. |
default |
(Optional) Displays the relay statistics information for the default VRF. |
No default behavior or values
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read |
The following is sample output from the show dhcp ipv4 relay statistics command when none of the optional keywords or arguments are used command :
RP/0/0/CPU0:router# show dhcp ipv4 relay statistics
Bridge | RX | TX | DR |
---------------------------------------------------------------------------------------
default | 0 | 0 | 0 |
The following is sample output from the show dhcp ipv4 relay statistics command using the vrf and default keywords:
RP/0/0/CPU0:router# show dhcp vrf default ipv4 relay statistics
Sun Apr 6 07:10:35.873 UTC
DHCP IPv4 Relay Statistics for VRF default:
TYPE | RECEIVE | TRANSMIT | DROP |
-------------------------------------------------------------------
DISCOVER | 0 | 0 | 0 |
OFFER | 0 | 0 | 0 |
REQUEST | 0 | 0 | 0 |
DECLINE | 0 | 0 | 0 |
ACK | 0 | 0 | 0 |
NAK | 0 | 0 | 0 |
RELEASE | 0 | 0 | 0 |
INFORM | 0 | 0 | 0 |
LEASEQUERY | 0 | 0 | 0 |
LEASEUNASSIGNED | 0 | 0 | 0 |
LEASEUNKNOWN | 0 | 0 | 0 |
LEASEACTIVE | 0 | 0 | 0 |
BOOTP-REQUEST | 0 | 0 | 0 |
BOOTP-REPLY | 0 | 0 | 0 |
BOOTP-INVALID | 0 | 0 | 0 |
To display the Dynamic Host Configuration Protocol (DHCP) unique identifier (DUID) on a specified device, use the show dhcp ipv6 command in EXEC mode.
show dhcp ipv6
No default behavior or values
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read |
The following is sample output from the show dhcp ipv6 command:
RP/0/0/CPU0:router# show dhcp ipv6
This device's DHCPv6 unique identifier(DUID): 000300010002FCA5DC1C
To display automatic client bindings from the Dynamic Host Configuration Protocol (DHCP) for IPv6 server binding table, use the show ipv6 dhcp binding command in EXEC mode.
show dhcp ipv6 binding [ipv6-address]
ipv6-address |
(optional) IPv6 address. The ipv6-address argument must be in the form documented in RFC 2373, where the address is specified in hexadecimal using 16-bit values between colons. |
No default behavior or values
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
The show dhcp ipv6 binding command displays all automatic client bindings from the DHCP for IPv6 server binding table if the ipv6-address argument is not specified. When the ipv6-address argument is specified, only the binding for the specified client is displayed.
Task ID |
Operations |
---|---|
ip-services |
read |
The following is sample output from the show dhcp ipv6 binding displaying all automatic client bindings from the DHCPv6 database. The ipv6 address argument is not specified:
RP/0/0/CPU0:router# show dhcp ipv6 binding
Client: FE80::202:FCFF:FEA5:DC39 (Ethernet2/1)
DUID: 000300010002FCA5DC1C
IA PD: IA ID 0x00040001, T1 0, T2 0
Prefix: 3FFE:C00:C18:11::/68
preferred lifetime 180, valid lifetime 12345
expires at Nov 08 2002 02:24 PM (12320 seconds)
Client: FE80::202:FCFF:FEA5:C039 (Ethernet2/1)
DUID: 000300010002FCA5C01C
IA PD: IA ID 0x00040001, T1 0, T2 0
Prefix: 3FFE:C00:C18:1::/72
preferred lifetime 240, valid lifetime 54321
expires at Nov 09 2002 02:02 AM (54246 seconds)
Prefix: 3FFE:C00:C18:2::/72
preferred lifetime 300, valid lifetime 54333
expires at Nov 09 2002 02:03 AM (54258 seconds)
Prefix: 3FFE:C00:C18:3::/72
preferred lifetime 280, valid lifetime 51111
expires at Nov 09 2002 01:09 AM (51036 seconds)
Field |
Description |
---|---|
DUID |
DHCP IPv6 unique identifier |
IA PD |
Identity Association for Prefix Delegation |
Prefix |
Prefixes delegated to the IAPD on the specified client |
To display the Dynamic Host Configuration Protocol (DHCP) for IPv6 binding database information, use the show dhcp ipv6 database command in EXEC mode.
show dhcp ipv6 database [agent-URL]
agent-URL |
(Optional) Flash, NVRAM, FTP, TFTP, or Remote Copy Protocol (RCP) uniform resource locator. |
location |
Displays the database information of the DHCPv6 node. |
location |
Name of the DHCPv6 node. |
None
Release |
Modification |
---|---|
This command was introduced. |
Each permanent storage to which the binding database is saved is called the database agent. An agent can be configured using the dhcp ipv6 database command. Supported database agents include FTP and TFTP servers, RCP, Flash file system, and NVRAM.
The show dhcp ipv6 database command displays DHCP for IPv6 binding database agent information. If the agent-URL argument is specified, only the specified agent is displayed. If the agent-URL argument is not specified, all database agents are shown.
Task ID | Operation |
---|---|
ip-services |
read |
This is a sample output from the show dhcp ipv6 database command:
RP/0/0/CPU0:router# show dhcp ipv6 database
Database agent tftp://172.19.216.133/db.tftp:
write delay: 69 seconds, transfer timeout: 300 seconds
last written at Jan 09 2003 01:54 PM,
write timer expires in 56 seconds
last read at Jan 06 2003 05:41 PM
successful read times 1
failed read times 0
successful write times 3172
failed write times 2
Database agent nvram:/dhcpv6-binding:
write delay: 60 seconds, transfer timeout: 300 seconds
last written at Jan 09 2003 01:54 PM,
write timer expires in 37 seconds
last read at never
successful read times 0
failed read times 0
successful write times 3325
failed write times 0
Database agent flash:/dhcpv6-db:
write delay: 82 seconds, transfer timeout: 3 seconds
last written at Jan 09 2003 01:54 PM,
write timer expires in 50 seconds
last read at never
successful read times 0
failed read times 0
successful write times 2220
failed write times 614
To display Dynamic Host Configuration Protocol (DHCP) for IPv6 interface information, use the show dhcp ipv6 interface command in EXEC mode.
show dhcp ipv6 interface interface-type interface-instance
interface-type |
Interface type. For more information, use the question mark (?) online help function. |
||
interface-instance |
Either a physical interface instance or a virtual interface instance as follows:
For more information about the syntax for the router, use the question mark (?) online help function. |
No default behavior or values
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
If no interfaces are specified, all interfaces on which DHCP for IPv6 (client or server) is enabled are shown. If an interface is specified, only information about the specified interface is displayed.
Task ID |
Operations |
---|---|
ip-services |
read |
The following is sample output from the show dhcp ipv6 interface command when an interface is not specified:
RP/0/0/CPU0:router
# show dhcp ipv6 interface
POS 0/5/0/0 is in server mode
Using pool: svr-p1
Preference value: 20
Hint from client: ignored
Rapid-Commit: ignored
Field |
Description |
---|---|
POS 0/5/0/0 is in server/relay mode |
Displays whether the specified interface is in server or relay mode. |
Using pool |
Name of the pool used by the interface. |
Preference value |
Advertised (or default of 0) preference value for the indicated server. |
Hint from client |
Displays whether the allow-hint has been enabled on the interface. |
Rapid-Commit |
Displays whether the rapid-commit keyword has been enabled on the interface. |
Command |
Description |
---|---|
Enables DHCP for IPv6 on an interface. |
To display Dynamic Host Configuration Protocol (DHCP) for IPv6 configuration information pool information, use the show ipv6 dhcp pool command in EXEC mode.
show dhcp ipv6 pool [pool-name]
pool-name |
(Optional) User-defined name for the local prefix pool. The pool name can be a symbolic string (such as "Engineering") or an integer (such as 0). |
No default behavior or values
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
Use the dhcp ipv6 pool command to create a configuration information pool, and use the dhcp ipv6 server command to associate the configuration information pool with a server on an interface.
The show dhcp ipv6 pool command displays DHCP for IPv6 configuration information pool information. If the poolname argument is specified, only information on the specified pool is displayed. If the poolname argument is not specified, all pools are shown.
Task ID |
Operations |
---|---|
ip-services |
read |
The following is sample output from the show dhcp ipv6 pool command. If pool-name is not specified, all pools are shown; otherwise, only the named pool is displayed.
RP/0/0/CPU0:router# show dhcp ipv6 pool
DHCPv6 pool: svr-p1
Static bindings:
Binding for client 000300010002FCA5C01C
IA PD: IA ID 00040002,
Prefix: 3FFE:C00:C18:3::/72
preferred lifetime 604800, valid lifetime 2592000
IA PD: IA ID not specified; being used by 00040001
Prefix: 3FFE:C00:C18:1::/72
preferred lifetime 240, valid lifetime 54321
Prefix: 3FFE:C00:C18:2::/72
preferred lifetime 300, valid lifetime 54333
Prefix: 3FFE:C00:C18:3::/72
preferred lifetime 280, valid lifetime 51111
DNS server: 1001::1
DNS server: 1001::2
Domain name: domain1.net
Domain name: domain2.net
Domain name: domain3.net
Active clients: 2
Field |
Description |
---|---|
DHCPv6 pool |
The name of the pool. |
IA PD |
Identity association for prefix delegation (IA PD), which is a collection of prefixes assigned to a client. |
Prefix |
Prefixes to be delegated to the indicated IAPD on the specified client. |
preferred lifetime, valid lifetime |
Lifetimes associated with the prefix statically assigned to the specified client. |
DNS server |
IPv6 addresses of the DNS servers. |
Domain name |
Displays the DNS domain search list. |
Active clients |
Total number of active clients. |
To configure a Session Initiation Protocol (SIP) server IPv6 address to be returned in the SIP server's IPv6 address list option to clients, use the sip address command in Dynamic Host Configuration Protocol (DHCP) IPv6 pool configuration mode. To disable this feature, use the no form of this command.
sip address ipv6 address
no sip address ipv6 address
ipv6-address |
IPv6 address. The ipv6-address argument must be in the form documented in RFC 2373, where the address is specified in hexadecimal using 16-bit values between colons. |
No default behavior or values
DHCP IPv6 pool configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
For the Dynamic Host Configuration Protocol (DHCP) for IPv6 server to obtain prefixes from RADIUS servers, the user must also configure the authorization, authentication, and accounting (AAA) client and PPP on the router. For information on how to configure the AAA client and PPP, see the “Implementing ADSL and Deploying Dial Access for IPv6” module of the Cisco IOS XR System Security Command Reference.
The sip address command configures a SIP server IPv6 address to be returned in the SIP server's IPv6 address list option to clients. To configure multiple SIP server addresses, issue this command multiple times. The new addresses do not overwrite old ones.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following example shows how to configure the SIP address using the sip-address command:
RP/0/0/CPU0:router(config)# dhcp ipv6 pool pool1 RP/0/0/CPU0:router(config-dhcpv6-pool)# sip address 10:10::10
Command |
Description |
---|---|
Configures a Dynamic Host Configuration Protocol (DHCP) for the IPv6 server configuration information pool and enters DHCP for IPv6 pool configuration mode. |
To configure a Session Initiation Protocol (SIP) server domain name to be returned in the SIP server's domain name list option to clients, use the sip domain-name command in Dynamic Host Configuration Protocol (DHCP) IPv6 pool configuration mode. To disable this feature, use the no form of this command.
sip domain-name domain-name
no sip domain-name domain-name
domain-name |
Domain name for a DHCP for IPv6 client. |
No default behavior or values
DHCP IPv6 pool configuration
Release |
Modification |
---|---|
Release 3.4.0 |
This command was introduced. |
For the Dynamic Host Configuration Protocol (DHCP) for IPv6 server to obtain prefixes from RADIUS servers, the user must also configure the authorization, authentication, and accounting (AAA) client and PPP on the router. For information on how to configure the AAA client and PPP, see the “Implementing ADSL and Deploying Dial Access for IPv6” module of the Cisco IOS XR System Security Command Reference.
The sip domain-name command configures a SIP server domain name to be returned in the SIP server's domain name list option to clients. To configure multiple SIP server domain names, issue this command multiple times. The new domain names do not overwrite old ones.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following example shows how to configure the SIP address using the sip domain-name command:
RP/0/0/CPU0:router(config)# dhcp ipv6 pool pool1 RP/0/0/CPU0:router(config-dhcpv6-pool)# sip domain-name domain1.com
Command |
Description |
---|---|
Configures a Dynamic Host Configuration Protocol (DHCP) for the IPv6 server configuration information pool and enters DHCP for IPv6 pool configuration mode. |
To configure a relay profile on a VPN routing and forwarding (VRF) instance, use the vrf (relay profile) command in Dynamic Host Configuration Protocol (DHCP) IPv4 configuration mode. To disable this feature, use the no form of this command.
vrf { vrf-name { relay } profile-name | default | all }
no vrf { vrf-name { relay } profile-name | default | all }
vrf-name |
User-defined name for the VRF. |
relay |
Specifies a relay profile. |
profile-name |
Specifies a name for the profile. |
default |
Specifies a profile for the default VRF. |
all |
Specifies a profile for all VRFs. |
If default is selected, then the configuration defaults to VRF.
DHCP IPv4 configuration
Release |
Modification |
---|---|
Release 3.7.0 |
This command was introduced. |
No specific guidelines impact the use of this command.
Task ID |
Operations |
---|---|
ip-services |
read, write |
The following example shows how to set the relay profile for all VRFs:
RP/0/0/CPU0:router# config RP/0/0/CPU0:router(config)# dhcp ipv4 RP/0/0/CPU0:router(config-dhcpv4)# vrf all
Command |
Description |
---|---|
Enables DHCP for IPv4 and enters DHCP IPv4 configuration mode. |
|
Configures how a relay agent processes BOOTREQUEST messages that already contain a nonzero giaddr attribute. |
|
Configures the DHCP relay agent to relay packets to a specific DHCP Server. |
|
Configures a DHCP server to validate the relay agent information option in forwarded BOOTREPLY messages. |
|
Enables the system to insert a DHCP relay agent information option in forwarded BOOTREQUEST messages to a DHCP server. |
|
Configures the DHCP component to not drop BOOTREQUEST messages that have the relay information option set and the giaddr set to zero. |
|
Configures how a relay agent processes BOOTREQUEST messages that already contain a relay information option. |