Cisco ASR 9000 Series Aggregation Services Router Broadband Network Gateway Command Reference, Release 5.1.x
IPv4 and IPv6 Commands
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IPv4 and IPv6 Commands

IPv4 and IPv6 Commands

This module describes the Cisco IOS XR software commands used to configure the IPv4 and IPv6 commands for Broadband Network Gateway (BNG) on the Cisco ASR 9000 Series Router. For details regarding the related configurations, refer to the Cisco ASR 9000 Series Aggregation Services Router Broadband Network Gateway Configuration Guide.

ipv4 mtu (BNG)

To set the maximum transmission unit (MTU) size of IPv4 packets sent on an interface, use the ipv4 mtu command in an appropriate configuration mode. To restore the default MTU size, use the no form of this command.

ipv4 mtu bytes

no ipv4 mtu

Syntax Description

bytes

MTU in bytes. Range is 68 to 65535 bytes for IPv4 packets. The maximum MTU size that can be set on an interface depends on the interface medium.

Command Default

If no MTU size is configured for IPv4 packets sent on an interface, the interface derives the MTU from the Layer 2 MTU.

Command Modes

Dynamic template configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.2.0

This command was supported in the dynamic template configuration mode for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The router punts the packets that needs fragmentation; whereas the software path drops the subscriber traffic that needs fragmentation.

The maximum MTU size that can be set on an interface depends on the interface medium. If the Layer 2 MTU is smaller than the Layer 3 MTU, the Cisco IOS XR software uses the Layer 2 MTU value for the Layer 3 MTU. Conversely, if the Layer 3 MTU is smaller than the Layer 2 MTU, the software uses Layer 3 MTU value. In other words the Cisco IOS XR software uses the lower of the two values for the MTU.

All devices on a physical medium must have the same protocol MTU to operate.

To enter the dynamic template configuration mode, run dynamic-template command in the global configuration mode.


Note


Changing the MTU value (with the mtu interface configuration command) can affect the IPv4 MTU value. If the current IPv4 MTU value is the same as the MTU value, and you change the MTU value, the IPv4 MTU value will be modified automatically to match the new MTU. However, the reverse is not true; changing the IPv4 MTU value has no effect on the value for the mtu command.


Task ID

Task ID

Operations

ipv4

read, write

network

read, write

config-services

read, write

Examples

This example shows how to set the maximum IPv4 packet size to 300 bytes in dynamic template configuration mode:
RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# dynamic-template type ppp p1
RP/0/RSP0/CPU0:router(config-dynamic-template-type)# ipv4 mtu 300

Related Commands

Command

Description

show ipv4 interface (BNG)

Displays the MTU status of interfaces configured for IPv4.

ipv4 unnumbered (point-to-point -BNG)

To enable IPv4 processing on a point-to-point interface without assigning an explicit IPv4 address to that interface, use the ipv4 unnumbered command in an appropriate configuration mode. To disable this feature, use the no form of this command.

ipv4 unnumbered interface-type interface-instance

no ipv4 unnumbered interface-type interface-instance

Syntax Description

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:

  • Physical interface instance. Naming notation is rack/slot/module/port and a slash between values is required as part of the notation.
    • rack: Chassis number of the rack.
    • slot: Physical slot number of the modular services card or line card.
    • module: Module number. A physical layer interface module (PLIM) is always 0.
    • port: Physical port number of the interface.
    Note   

    In references to a Management Ethernet interface located on a route processor card, the physical slot number is alphanumeric (RSP0 ) and the module is CPU0. Example: interface MgmtEth0/RSP0 /CPU0/0.

  • Virtual interface instance. Number range varies depending on interface type.

For more information about the syntax for the router, use the question mark (?) online help function.

Command Default

IPv4 processing on a point-to-point interface is disabled unless an IPv4 address is assigned explicitly to that interface.

Command Modes

Dynamic template configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.2.0

This command was supported in the dynamic template configuration mode for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

To enter the dynamic template configuration mode, run dynamic-template command in the global configuration mode.

Whenever the unnumbered interface generates a packet (for example, for a routing update), it uses the address of the specified interface as the source address of the IPv4 packet. It also uses the IPv4 address of the specified interface in determining which routing processes are sending updates over the unnumbered interface. Restrictions include the following:

  • You cannot use the ping EXEC command to determine whether the interface is up because the interface has no address. Simple Network Management Protocol (SNMP) can be used to remotely monitor interface status.

The interface you specify by the interface-type and interface-number arguments must be enabled (listed as “up” in the show interfaces command display).

Task ID

Task ID

Operations

ipv4

read, write

network

read, write

config-services

read, write

Examples

In this example the Bundle-Ether interface is assigned address 100.10 in the dynamic template configuration mode:
RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# dynamic-template type ppp p1
RP/0/RSP0/CPU0:router(config-dynamic-template-type)# ipv4 unnumbered Bundle-Ether100.10

ipv4 unreachables disable (BNG)

To disable the generation of IPv4 Internet Control Message Protocol (ICMP) unreachable messages, use the ipv4 unreachables disable command in an appropriate configuration mode. To re-enable the generation of ICMP unreachable messages, use the no form of this command.

ipv4 unreachables disable

no ipv4 unreachables disable

Syntax Description

This command has no keywords or arguments.

Command Default

IPv4 ICMP unreachables messages are generated.

Command Modes

Dynamic template configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.2.0

This command was supported in the dynamic template configuration mode for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

If the software receives a nonbroadcast packet destined for itself that uses a protocol it does not recognize, it sends an ICMP protocol unreachable message to the source.

If the software receives a datagram that it cannot deliver to its ultimate destination because it knows of no route to the destination address, it replies to the originator of that datagram with an ICMP host unreachable message.

This command affects a number of ICMP unreachable messages.

To enter the dynamic template configuration mode, run dynamic-template command in the global configuration mode.

Task ID

Task ID

Operations

ipv4

read, write

network

read, write

config-services

read, write

Examples

This example shows how to disable the generation of ICMP unreachable messages on dynamic template configuration mode:
RP/0/RSP0/CPU0:router(config)# dynamic-template type ppp foo
RP/0/RSP0/CPU0:router(config-dynamic-template-type)# ipv4 unreachables disable

ipv4 verify unicast source reachable-via (BNG)

To enable IPv4 unicast Reverse Path Forwarding (RPF) checking, use the ipv4 verify unicast source reachable-via command in an appropriate configuration mode. To disable unicast RPF, use the no form of this command.

ipv4 verify unicast source reachable-via { any | rx } [allow-default] [allow-self-ping]

no ipv4 verify unicast source reachable-via { any | rx } [allow-default] [allow-self-ping]

Syntax Description

any

Enables loose unicast RPF checking. If loose unicast RPF is enabled, a packet is not forwarded unless its source prefix exists in the routing table.

rx

Enables strict unicast RPF checking. If strict unicast RPF is enabled, a packet is not forwarded unless its source prefix exists in the routing table and the output interface matches the interface on which the packet was received.

allow-default

(Optional) Enables the matching of default routes. This option applies to both loose and strict RPF.

allow-self-ping

(Optional) Enables the router to ping out an interface.This option applies to both loose and strict RPF.

Command Default

IPv4 unicast RPF is disabled.

Command Modes

Dynamic template configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.2.0

This command was supported in the dynamic template configuration mode for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

To enter the dynamic template configuration mode, run dynamic-template command in the global configuration mode.

Use the ipv4 verify unicast source reachable-via interface command to mitigate problems caused by malformed or forged (spoofed) IP source addresses that pass through a router. Malformed or forged source addresses can indicate denial-of-service (DoS) attacks based on source IP address spoofing.

When strict unicast RPF is enabled on an interface, the router examines all packets received on that interface. The router checks to make sure that the source address appears in the routing table and matches the interface on which the packet was received.

When loose unicast RPF is enabled on an interface, the router examines all packets received on that interface. The router checks to make sure that the source address can be reached through any of the router interfaces.

Task ID

Task ID

Operations

ipv4

read, write

network

read, write

config-services

read, write

Examples

This example shows how to configure strict RPF on dynamic template configuration mode:
RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# dynamic-template type ppp p1
RP/0/RSP0/CPU0:router(config-dynamic-template-type)# ipv4 verify unicast source reachable-via rx

ipv6 enable (BNG)

To enable IPv6 processing on an interface that has not been configured with an explicit IPv6 address, use the ipv6 enable command in an appropriate configuration mode. To disable IPv6 processing on an interface that has not been configured with an explicit IPv6 address, use the no form of this command.

ipv6 enable

no ipv6 enable

Syntax Description

This command has no keywords or arguments.

Command Default

IPv6 is disabled.

Command Modes

Dynamic template configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.3.0

This command was supported in the dynamic template configuration mode for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The ipv6 enable command automatically configures an IPv6 link-local unicast address on the interface while also enabling the interface for IPv6 processing. The no ipv6 enable command does not disable IPv6 processing on an interface that is configured with an explicit IPv6 address.

To enter the dynamic template configuration mode, run dynamic-template command in the global configuration mode.

Task ID

Task ID

Operations

ipv6

read, write

network

read, write

config-services

read, write

Examples

This example show how to enable IPv6 processing on dynamic template configuration mode:
RP/0/RSP0/CPU0:router(config)# dynamic-template type ppp foo
RP/0/RSP0/CPU0:router(config-dynamic-template-type)# ipv6 enable

Related Commands

Command

Description

show ipv6 interface (BNG)

Displays the usability status of interfaces configured for IPv6.

ipv6 mtu (BNG)

To set the maximum transmission unit (MTU) size of IPv6 packets sent on an interface, use the ipv6 mtu command in an appropriate configuration mode. To restore the default MTU size, use the no form of this command.

ipv6 mtu bytes

no ipv6 mtu

Syntax Description

bytes

MTU in bytes. Range is 1280 to 65535 for IPv6 packets. The maximum MTU size that can be set on an interface depends on the interface medium.

Command Default

If no MTU size is configured for IPv6 packets sent on an interface, the interface derives the MTU from the Layer 2 MTU.

Command Modes

Dynamic template configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.3.0

This command was supported in the dynamic template configuration mode for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

If an IPv6 packet exceeds the MTU set for the interface, only the source router of the packet can fragment it.

The maximum MTU size that can be set on an interface depends on the interface medium. If the Layer 2 MTU is smaller than the Layer 3 MTU, the Cisco IOS XR software uses the Layer 2 MTU value for the Layer 3 MTU. Conversely, If the Layer 3 MTU is smaller than the Layer 2 MTU, the software uses Layer 3 MTU value. In other words the Cisco IOS XR software uses the lower of the two values for the MTU.

All devices on a physical medium must have the same protocol MTU to operate.

To enter the dynamic template configuration mode, run dynamic-template command in the global configuration mode.


Note


Changing the MTU value (with the mtu interface configuration command) can affect the IPv6 MTU value. If the current IPv6 MTU value is the same as the MTU value, and you change the MTU value, the IPv6 MTU value will be modified automatically to match the new MTU. However, the reverse is not true; changing the IPv6 MTU value has no effect on the value for the mtu command.


Task ID

Task ID

Operations

ipv6

read, write

network

read, write

config-services

read, write

Examples

This example shows how to set the maximum IPv6 packet size to 1350 bytes in the dynamic template configuration mode:
RP/0/RSP0/CPU0:router(config)# dynamic-template type ppp foo
RP/0/RSP0/CPU0:router(config-dynamic-template-type)# ipv6 mtu 1350

Related Commands

Command

Description

show ipv6 interface (BNG)

Displays the usability status of interfaces configured for IPv6.

ipv6 unreachables disable (BNG)

To disable the generation of IPv6 Internet Control Message Protocol (ICMP) unreachable messages, use the ipv6 unreachables disable command in an appropriate configuration mode. To re-enable the generation of ICMP unreachable messages, use the no form of this command.

ipv6 unreachables disable

no ipv6 unreachables disable

Syntax Description

This command has no keywords or arguments.

Command Default

IPv6 ICMP unreachables messages are generated.

Command Modes

Dynamic template configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.3.0

This command was supported in the dynamic template configuration mode for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

If the software receives a nonbroadcast packet destined for itself that uses a protocol it does not recognize, it sends an ICMP protocol unreachable message to the source.

If the software receives a datagram that it cannot deliver to its ultimate destination because it knows of no route to the destination address, it replies to the originator of that datagram with an ICMP host unreachable message.

This command affects a number of ICMP unreachable messages.

To enter the dynamic template configuration mode, run dynamic-template command in the global configuration mode.

Task ID

Task ID

Operations

ipv6

read, write

network

read, write

config-services

read, write

Examples

This example shows how to disable the generation of ICMP unreachable messages on dynamic template configuration mode:
RP/0/RSP0/CPU0:router(config)# dynamic-template type ppp foo
RP/0/RSP0/CPU0:router(config-dynamic-template-type)# ipv6 unreachables disable

show ipv4 interface (BNG)

To display the usability status of interfaces configured for IPv4, use the show ipv4 interface command in the EXEC mode.

show ipv4 [ vrf vrf-name ] interface [ type interface-path-id | brief | summary ]

Syntax Description

vrf

(Optional)  Displays VPN routing and forwarding (VRF) instance information.

vrf-name

(Optional) Name of a VRF.

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 as follows:

  • Physical interface instance. Naming notation is rack/slot/module/port and a slash between values is required as part of the notation.
    • rack: Chassis number of the rack.
    • slot: Physical slot number of the modular services card or line card.
    • module: Module number. A physical layer interface module (PLIM) is always 0.
    • port: Physical port number of the interface.
    Note   

    In references to a Management Ethernet interface located on a route processor card, the physical slot number is alphanumeric (RSP0 ) and the module is CPU0. Example: interface MgmtEth0/RSP0 /CPU0/0.

  • Virtual interface instance. Number range varies depending on interface type.

For more information about the syntax for the router, use the question mark (?) online help function.

brief

(Optional) Displays the primary IPv4 addresses configured on the router’s interfaces and their protocol and line states.

summary

(Optional) Displays the number of interfaces on the router that are assigned, unassigned, or unnumbered.

Command Default

If VRF is not specified, the software displays the default VRF.

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.2.0

This command was supported for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The show ipv4 interface command provides output similar to the show ipv6 interface command, except that it is IPv4-specific.

The interface name will be displayed only if the name belongs to the VRF instance. If the vrf-name is not specified then the interface instance will be displayed only if the interface belongs to the default VRF.

Task ID

Task ID

Operations

ipv4

read

network

read

Examples

This is the sample output of the show ipv4 interface command:

RP/0/RSP0/CPU0:router# show ipv4 interface

Loopback0 is Up, line protocol is Up
  Internet address is 10
.0.0.1/8

  Secondary address 10.0.0.2/8
  MTU is 1514 (1514 is available to IP)
  Multicast reserved groups joined: 10.0.0.1
  Directed broadcast forwarding is disabled
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
gigabitethernet0/0/0/0 is Up, line protocol is Up
  Internet address is 10.25.58.1/16
  MTU is 1514 (1500 is available to IP)
  Multicast reserved groups joined: 10.0.224.1
  Directed broadcast forwarding is disabled
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
gigabitethernet0/0/0/0 is Shutdown, line protocol is Down
  Vrf is default (vrfid 0x60000000)
  Internet protocol processing disabled

This table describes the significant fields shown in the display.



Table 1 show ipv4 interface Command Field Descriptions

Field

Description

Loopback0 is Up

If the interface hardware is usable, the interface is marked “Up.” For an interface to be usable, both the interface hardware and line protocol must be up.

line protocol is Up

If the interface can provide two-way communication, the line protocol is marked “Up.” For an interface to be usable, both the interface hardware and line protocol must be up.

Internet address

IPv4 Internet address and subnet mask of the interface.

Secondary address

Displays a secondary address, if one has been set.

MTU

Displays the IPv4 MTU1 value set on the interface.

Multicast reserved groups joined

Indicates the multicast groups this interface belongs to.

Directed broadcast forwarding

Indicates whether directed broadcast forwarding is enabled or disabled.

Outgoing access list

Indicates whether the interface has an outgoing access list set.

Inbound access list

Indicates whether the interface has an incoming access list set.

Proxy ARP

Indicates whether proxy ARP2 is enabled or disabled on an interface.

ICMP redirects

Specifies whether ICMPv43 redirects are sent on this interface.

ICMP unreachables

Specifies whether unreachable messages are sent on this interface.

Internet protocol processing disabled

Indicates an IPv4 address has not been configured on the interface.

1 MTU = maximum transmission unit
2 ARP = Address Resolution Protocoladdress resolution protocol
3 ICMPv4 = Internet Control Message Protocol internet control message protocol version 4

Related Commands

Command

Description

show ipv6 interface (BNG)

Displays the usability status of interfaces configured for IPv6.

show ipv4 traffic (BNG)

To display the IPv4 traffic statistics, use the show ipv4 traffic command in the EXEC mode.

show ipv4 traffic [brief]

Syntax Description

brief

(Optional) Displays only IPv4 and Internet Control Message Protocol version 4 (ICMPv4) traffic.

Command Default

None

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced .

Release 4.2.0

This command was supported for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The show ipv4 traffic command provides output similar to the show ipv6 traffic command, except that it is IPv4-specific.

Task ID

Task ID

Operations

ipv4

read

network

read

Examples

This is the sample output of the show ipv4 traffic command:

RP/0/RSP0/CPU0:router# show ipv4 traffic

IP statistics:
  Rcvd:  16372 total, 16372 local destination
         0 format errors, 0 bad hop count
         0 unknown protocol, 0 not a gateway
         0 security failures, 0 bad source, 0 bad header
         0 with options, 0 bad, 0 unknown
  Opts:  0 end, 0 nop, 0 basic security, 0 extended security
         0 strict source rt, 0 loose source rt, 0 record rt
         0 stream ID, 0 timestamp, 0 alert, 0 cipso
  Frags: 0 reassembled, 0 timeouts, 0 couldn't reassemble
         0 fragmented, 0 fragment count
  Bcast: 0 sent, 0 received
  Mcast: 0 sent, 0 received
   Drop: 0 encapsulation failed, 0 no route, 0 too big, 0 sanity address check
   Sent: 16372 total

ICMP statistics:
  Sent: 0 admin unreachable, 0 network unreachable
        0 host unreachable, 0 protocol unreachable
        0 port unreachable, 0 fragment unreachable
        0 time to live exceeded, 0 reassembly ttl exceeded
        5 echo request, 0 echo reply
        0 mask request, 0 mask reply
        0 parameter error, 0 redirects
        5 total
  Rcvd: 0 admin unreachable, 0 network unreachable
        2 host unreachable, 0 protocol unreachable
        0 port unreachable, 0 fragment unreachable
        0 time to live exceeded, 0 reassembly ttl exceeded
        0 echo request, 5 echo reply
        0 mask request, 0 mask reply
        0 redirect, 0 parameter error
        0 source quench, 0 timestamp, 0 timestamp reply
        0 router advertisement, 0 router solicitation
        7 total, 0 checksum errors, 0 unknown

UDP statistics:
        16365 packets input, 16367 packets output
        0 checksum errors, 0 no port
        0 forwarded broadcasts

TCP statistics:
        0 packets input, 0 packets output
        0 checksum errors, 0 no port

This table describes the significant fields shown in the display.



Table 2 show ipv4 traffic Command Field Descriptions

Field

Description

bad hop count

Occurs when a packet is discarded because its TTL4 field was decremented to zero.

encapsulation failed

Usually indicates that the router had no ARP request entry and therefore did not send a datagram.

format errors

Indicates a gross error in the packet format, such as an impossible Internet header length.

IP statistics Rcvd total

Indicates the total number of local destination and other packets received in the software plane. It does not account for the IP packets forwarded or discarded in hardware.

no route

Counted when the Cisco IOS XR software discards a datagram it did not know how to route.

4 TTL = time-to-live

Related Commands

Command

Description

show ipv6 traffic (BNG)

Displays statistics about IPv6 traffic.

show ipv6 interface (BNG)

To display the usability status of interfaces configured for IPv6, use the show ipv6 interface command in the EXEC mode.

show ipv6 [ vrf vrf-name ] interface [ type interface-path-id | brief | summary ]

Syntax Description

vrf

(Optional)  Displays VPN routing and forwarding (VRF) instance information.

vrf-name

(Optional) Name of a VRF.

type

(Optional) Interface type. For more information, use the question mark (?) online help function.

interface-path-id

(Optional) Either a physical interface instance or a virtual interface instance as follows:

  • Physical interface instance. Naming notation is rack/slot/module/port and a slash between values is required as part of the notation.
    • rack: Chassis number of the rack.
    • slot: Physical slot number of the modular services card or line card.
    • module: Module number. A physical layer interface module (PLIM) is always 0.
    • port: Physical port number of the interface.
    Note   

    In references to a Management Ethernet interface located on a route processor card, the physical slot number is alphanumeric (RSP0) and the module is CPU0. Example: interface MgmtEth0/RSP0 /CPU0/0.

  • Virtual interface instance. Number range varies depending on interface type.

For more information about the syntax for the router, use the question mark (?) online help function.

brief

(Optional) Displays the primary IPv6 addresses configured on the router interfaces and their protocol and line states.

summary

(Optional) Displays the number of interfaces on the router that are assigned, unassigned, or unnumbered.

Command Default

None

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.3.0

This command was supported for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The show ipv6 interface command provides output similar to the show ipv4 interface command, except that it is IPv6-specific.

Task ID

Task ID

Operations

ipv6

read

Examples

This is the sample output of the show ipv6 interface command:

RP/0/RSP0/CPU0:router# show ipv6 interface 

GigabitEthernet0/2/0/0 is Up, line protocol is Up, Vrfid is default (0x60000000)
  IPv6 is enabled, link-local address is fe80::212:daff:fe62:c150 
  Global unicast address(es):
    202::1, subnet is 202::/64 
  Joined group address(es): ff02::1:ff00:1 ff02::1:ff62:c150 ff02::2
      ff02::1
  MTU is 1514 (1500 is available to IPv6)
  ICMP redirects are disabled
  ICMP unreachables are enabled
  ND DAD is enabled, number of DAD attempts 1
  ND reachable time is 0 milliseconds
  ND advertised retransmit interval is 0 milliseconds
  ND router advertisements are sent every 200 seconds
  ND router advertisements live for 1800 seconds
  Hosts use stateless autoconfig for addresses.
  Outgoing access list is not set
  Inbound  access list is not set

This table describes the significant fields shown in the display.



Table 3 show ipv6 interface Command Field Descriptions

Field

Description

GigabitEthernet0 /3/0/0 is Shutdown, line protocol is Down

Indicates whether the interface hardware is currently active (whether line signal is present) and whether it has been taken down by an administrator. If the interface hardware is usable, the interface is marked “Up.” For an interface to be usable, both the interface hardware and line protocol must be up.

line protocol is Up (or down)

Indicates whether the software processes that handle the line protocol consider the line usable (that is, whether keepalives are successful). If the interface can provide two-way communication, the line protocol is marked “Up.” For an interface to be usable, both the interface hardware and line protocol must be up.

IPv6 is enabled, stalled, disabled (stalled and disabled are not shown in sample output)

Indicates that IPv6 is enabled, stalled, or disabled on the interface. If IPv6 is enabled, the interface is marked “enabled.” If duplicate address detection processing identified the link-local address of the interface as being a duplicate address, the processing of IPv6 packets is disabled on the interface and the interface is marked “stalled.” If IPv6 is not enabled, the interface is marked “disabled.”

link-local address

Displays the link-local address assigned to the interface.

TENTATIVE

The state of the address in relation to duplicate address detection. States can be any of the following:

  • duplicate—The address is not unique and is not being used. If the duplicate address is the link-local address of an interface, the processing of IPv6 packets is disabled on that interface.
  • tentative—Duplicate address detection is either pending or under way on this interface.
Note   

If an address does not have one of these states (the state for the address is blank), the address is unique and is being used.

Global unicast addresses

Displays the global unicast addresses assigned to the interface.

ICMP redirects

State of Internet Control Message Protocol (ICMP) IPv6 redirect messages on the interface (the sending of the messages is enabled or disabled).

ND DAD

State of duplicate address detection on the interface (enabled or disabled).

number of DAD attempts

Number of consecutive neighbor solicitation messages that are sent on the interface while duplicate address detection is performed.

ND reachable time

Displays the neighbor discovery reachable time (in milliseconds) assigned to this interface.

Related Commands

Command

Description

show ipv4 interface (BNG)

Displays the usability status of interfaces configured for IPv4.

show ipv6 neighbors (BNG)

To display the IPv6 neighbor discovery cache information, use the show ipv6 neighbors command in the EXEC mode.

show ipv6 neighbors [ type interface-path-id | location node-id ]

Syntax Description

type

(Optional) Interface type. For more information, use the question mark (?) online help function.

interface-path-id

(Optional) Physical interface instance or a virtual interface.

Note   

Use the show interfaces command to see a list of all interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

location node-id

(Optional) Designates a node. The node-id argument is entered in the rack/slot/module notation.

Command Default

All IPv6 neighbor discovery cache information is displayed.

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.3.0

This command was supported for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

When the interface-type and interface-number arguments are not specified, cache information for all IPv6 neighbors is displayed. Specifying the interface-type and interface-number arguments displays only cache information about the specified interface.

Task ID

Task ID

Operations

ipv6

read

Examples

This is the sample output of the show ipv6 neighbors command when entered with an interface type and number:
RP/0/RSP0/CPU0:router# show ipv6 neighbors gigabitethernet 0/0/0/0

IPv6 Address                              Age Link-layer Addr State Interface
2000:0:0:4::2                               0 0003.a0d6.141e  REACH gigabitethernet2
FE80::203:A0FF:FED6:141E                    0 0003.a0d6.141e  REACH gigabitethernet2
3001:1::45a                                 - 0002.7d1a.9472  REACH gigabitethernet2

This is the sample output of the show ipv6 neighbors command when entered with an IPv6 address:
RP/0/RSP0/CPU0:router# show ipv6 neighbors 2000:0:0:4::2

IPv6 Address                              Age Link-layer Addr State Interface
2000:0:0:4::2                               0 0003.a0d6.141e  REACH gigabitethernet2

This is the sample output of the show ipv6 neighbors command:

RP/0/RSP0/CPU0:router# show ipv6 neighbors 

IPv6 Address     Age Link-layer Addr State Interface    Location
2001:1::3        130  0011.9400.0003 REACH BE1          0/0/CPU0       
2001:1::4        335  0011.9400.0004 REACH BE1          0/0/CPU0       
2001:1::5        314  0011.9400.0005 REACH BE1          0/0/CPU0       
2001:1::6        291  0011.9400.0006 REACH BE1          0/0/CPU0       
2001:1::7        235  0011.9400.0007 REACH BE1          0/0/CPU0       
2001:1::8        340  0011.9400.0008 REACH BE1          0/0/CPU0       
2001:1::9        230  0011.9400.0009 REACH BE1          0/0/CPU0       
2001:1::a        99   0011.9400.000a REACH BE1          0/0/CPU0       
2001:1::b        291  0011.9400.000b REACH BE1          0/0/CPU0       
2001:1::c        226  0011.9400.000c REACH BE1          0/0/CPU0       
2001:1::d        272  0011.9400.000d REACH BE1          0/0/CPU0       
2001:1::e        14   0011.9400.000e REACH BE1          0/0/CPU0       
2001:1::f        299  0011.9400.000f REACH BE1          0/0/CPU0       
2001:1::10       131  0011.9400.0010 REACH BE1          0/0/CPU0       
2001:1::11       70   0011.9400.0011 REACH BE1          0/0/CPU0       
2001:1::12       131  0011.9400.0012 REACH BE1          0/0/CPU0       
2001:1::13       137  0011.9400.0013 REACH BE1          0/0/CPU0       
2001:1::14       290  0011.9400.0014 REACH BE1          0/0/CPU0       
2001:1::15       19   0011.9400.0015 REACH BE1          0/0/CPU0       
2001:1::16       158  0011.9400.0016 REACH BE1          0/0/CPU0       
2001:1::17       35   0011.9400.0017 REACH BE1          0/0/CPU0       
2001:1::18       222  0011.9400.0018 REACH BE1          0/0/CPU0    

This is the sample output of the show ipv6 neighbors command when entered with a location:

RP/0/RSP0/CPU0:router# show ipv6 neighbors  location 0/2/CPU0 

IPv6 Address    Age Link-layer Addr State Interface     Location
2001:3::2       119  0013.9400.0002 REACH BE3           0/2/CPU0       
2001:3::3       179  0013.9400.0003 DELAY BE3           0/2/CPU0       
2001:3::4       166  0013.9400.0004 REACH BE3           0/2/CPU0       
2001:3::5       78   0013.9400.0005 REACH BE3           0/2/CPU0       
2001:3::6       19   0013.9400.0006 REACH BE3           0/2/CPU0       
2001:3::7       173  0013.9400.0007 REACH BE3           0/2/CPU0       
2001:3::8       140  0013.9400.0008 REACH BE3           0/2/CPU0       
2001:3::9       163  0013.9400.0009 REACH BE3           0/2/CPU0       
2001:3::a       40   0013.9400.000a REACH BE3           0/2/CPU0       
2001:3::b       90   0013.9400.000b REACH BE3           0/2/CPU0       
2001:3::c       35   0013.9400.000c REACH BE3           0/2/CPU0       
2001:3::d       114  0013.9400.000d REACH BE3           0/2/CPU0       
2001:3::e       117  0013.9400.000e REACH BE3           0/2/CPU0       
2001:3::f       157  0013.9400.000f REACH BE3           0/2/CPU0       
2001:3::10      9    0013.9400.0010 REACH BE3           0/2/CPU0       
2001:3::11      120  0013.9400.0011 REACH BE3           0/2/CPU0       
2001:3::12      87   0013.9400.0012 REACH BE3           0/2/CPU0       
2001:3::13      180  0013.9400.0013 DELAY BE3           0/2/CPU0       
2001:3::14      103  0013.9400.0014 REACH BE3           0/2/CPU0       
2001:3::15      132  0013.9400.0015 REACH BE3           0/2/CPU0       
2001:3::16      33   0013.9400.0016 REACH BE3           0/2/CPU0       
2001:3::17      150  0013.9400.0017 REACH BE3           0/2/CPU0       
2001:3::18      117  0013.9400.0018 REACH BE3           0/2/CPU0       
2001:3::19      48   0013.9400.0019 REACH BE3           0/2/CPU0       
2001:3::1a      67   0013.9400.001a REACH BE3           0/2/CPU0       
2001:3::1b      91   0013.9400.001b REACH BE3           0/2/CPU0       
2001:3::1c      33   0013.9400.001c REACH BE3           0/2/CPU0       
2001:3::1d      174  0013.9400.001d DELAY BE3           0/2/CPU0       
2001:3::1e      144  0013.9400.001e REACH BE3           0/2/CPU0       
2001:3::1f      121  0013.9400.001f REACH BE3           0/2/CPU0       
2001:3::20      53   0013.9400.0020 REACH BE3           0/2/CPU0      

This table describes significant fields shown in the display.



Table 4 show ipv6 neighbors Command Field Descriptions

Field

Description

IPv6 Address

IPv6 address of neighbor or interface.

Age

Time (in minutes) since the address was confirmed to be reachable. A hyphen (-) indicates a static entry.

Link-layer Addr

MAC address. If the address is unknown, a hyphen (-) is displayed.

State

The state of the neighbor cache entry. These are the states for dynamic entries in the IPv6 neighbor discovery cache:

  • INCMP (incomplete)—Address resolution is being performed on the entry. A neighbor solicitation message has been sent to the solicited-node multicast address of the target, but the corresponding neighbor advertisement message has not yet been received.
  • reach (reachable)—Positive confirmation was received within the last ReachableTime milliseconds that the forward path to the neighbor was functioning properly. While in reach state, the device takes no special action as packets are sent.
  • stale—More than ReachableTime milliseconds have elapsed since the last positive confirmation was received that the forward path was functioning properly. While in stale state, the device takes no action until a packet is sent.
  • delay—More than ReachableTime milliseconds have elapsed since the last positive confirmation was received that the forward path was functioning properly. A packet was sent within the last DELAY_FIRST_PROBE_TIME seconds. If no reachability confirmation is received within DELAY_FIRST_PROBE_TIME seconds of entering the delay state, send a neighbor solicitation message and change the state to probe.
  • probe—A reachability confirmation is actively sought by resending neighbor solicitation messages every RetransTimer milliseconds until a reachability confirmation is received.

These are the possible states for static entries in the IPv6 neighbor discovery cache:

  • reach (reachable)—The interface for this entry is up.
  • INCMP (incomplete)—The interface for this entry is down.
Note   

Reachability detection is not applied to static entries in the IPv6 neighbor discovery cache; therefore, the descriptions for the INCMP (incomplete) and reach (reachable) states are different for dynamic and static cache entries.

Interface

Interface from which the address is reachable.

Related Commands

Command

Description

show ipv6 neighbors summary (BNG)

Displays summary information for the neighbor entries.

show ipv6 neighbors summary (BNG)

To display summary information for the neighbor entries, use the show ipv6 neighbors summary command in the EXEC mode.

show ipv6 neighbors summary

Syntax Description

This command has no keywords or arguments.

Command Default

The default value is disabled.

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.3.0

This command was supported for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID

Operations

ipv6

read

Examples

This is the sample output of the show ipv6 neighbors summary command that shows the summary information for the neighbor entries:

RP/0/RSP0/CPU0:router# show ipv6 neighbors summary

Mcast nbr entries:
    Subtotal: 0
Static nbr entries:
    Subtotal: 0
Dynamic nbr entries:
    Subtotal: 0

Total nbr entries: 0

Related Commands

Command

Description

show ipv6 neighbors (BNG)

Displays IPv6 neighbor discovery cache information.

show ipv6 traffic (BNG)

To display the IPv6 traffic statistics, use the show traffic command in the EXEC mode.

show ipv6 traffic [brief]

Syntax Description

brief

(Optional) Displays only IPv6 and Internet Control Message Protocol version 6 (ICMPv6) traffic statistics.

Command Default

None

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.3.0

This command was supported for BNG.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The show ipv6 traffic command provides output similar to the show ipv4 traffic command, except that it is IPv6-specific.

Task ID

Task ID

Operations

ipv6

read

network

read

Examples

This is the sample output of the show ipv6 traffic command:

RP/0/RSP0/CPU0:router# show ipv6 traffic

	IPv6 statistics:
  Rcvd:  0 total, 0 local destination
         0 source-routed, 0 truncated
         0 format errors, 0 hop count exceeded
         0 bad header, 0 unknown option, 0 bad source
         0 unknown protocol
         0 fragments, 0 total reassembled
         0 reassembly timeouts, 0 reassembly failures
         0 reassembly max drop
         0  sanity address check drops
  Sent:  0 generated, 0 forwarded
         0 fragmented into 0 fragments, 0 failed
         0 no route, 0 too big
  Mcast: 0 received, 0 sent

ICMP statistics:
  Rcvd: 0 input, 0 checksum errors, 0 too short
        0 unknown error type
        unreach: 0 routing, 0 admin, 0 neighbor,
                 0 address, 0 port, 0 unknown
        parameter: 0 error, 0 header, 0 option,
                   0 unknown
        0 hopcount expired, 0 reassembly timeout,
        0 unknown timeout, 0 too big,
        0 echo request, 0 echo reply
  Sent: 0 output, 0 rate-limited
        unreach: 0 routing, 0 admin, 0 neighbor,
                 0 address, 0 port, 0 unknown
        parameter: 0 error, 0 header, 0 option
                 0 unknown
        0 hopcount expired, 0 reassembly timeout,
        0 unknown timeout, 0 too big,
        0 echo request, 0 echo reply

Neighbor Discovery ICMP statistics:
  Rcvd: 0 router solicit, 0 router advert, 0 redirect
        0 neighbor solicit, 0 neighbor advert
  Sent: 0 router solicit, 0 router advert, 0 redirect
        0 neighbor solicit, 0 neighbor advert

UDP statistics:
        0 packets input, 0 checksum errors
        0 length errors, 0 no port, 0 dropped
        0 packets output

TCP statistics:s
        0 packets input, 0 checksum errors, 0 dropped
        0 packets output, 0 retransmitted

This table describes the significant fields shown in the display.



Table 5 show ipv6 traffic Command Field Descriptions

Field

Description

Rcvd:

Statistics in this section refer to packets received by the router.

total

Total number of packets received by the software.

local destination

Locally destined packets received by the software.

source-routed

Packets seen by the software with RH.

truncated

Truncated packets seen by the software.

bad header

An error was found in generic HBH, RH, DH, or HA. Software only.

unknown option

Unknown option type in IPv6 header.

unknown protocol

Protocol specified in the IP header of the received packet is unreachable.

Sent:

Statistics in this section refer to packets sent by the router.

forwarded

Packets forwarded by the software. If the packet cannot be forwarded in the first lookup (for example, the packet needs option processing), then the packet is not included in this count, even if it ends up being forwarded by the software.

Mcast:

Multicast packets.

ICMP statistics:

Internet Control Message Protocol statistics.

Related Commands

Command

Description

show ipv4 traffic (BNG)

Displays statistics about IPv4 traffic.