To display the usability status of interfaces configured for IPv6, use the
show
ipv6
interface command in user EXEC or privileged EXEC mode.
show ipv6 interface [brief] [type number] [prefix]
Syntax Description
brief
|
(Optional) Displays a brief summary of IPv6 status and configuration for each interface.
|
type
|
(Optional) The interface type about which to display information.
|
|
|
|
|
number
|
(Optional) The interface number about which to display information.
|
prefix
|
(Optional) Prefix generated from a local IPv6 prefix pool.
|
Command Default
All IPv6 interfaces are displayed.
Command Modes
User EXEC
Privileged EXEC
Command History
Release
|
Modification
|
12.2(2)T
|
This command was introduced.
|
12.2(4)T
|
The OK, TENTATIVE, DUPLICATE, ICMP redirects, and ND DAD fields were added to the command output.
|
12.0(21)ST
|
This command was integrated into Cisco IOS Release 12.0(21)ST.
|
12.0(22)S
|
This command was integrated into Cisco IOS Release 12.0(22)S.
|
12.2(14)S
|
This command was integrated into Cisco IOS Release 12.2(14)S.
|
12.2(25)S
|
Command output was updated to display information on the current Unicast RPF configuration.
|
12.4(2)T
|
Command output was updated to show the state of the default router preference (DRP) preference value as advertised by a device
through an interface.
|
12.2(28)SB
|
This command was integrated into Cisco IOS Release 12.2(28)SB.
|
12.2(25)SG
|
This command was integrated into Cisco IOS Release 12.2(25)SG.
|
12.4(4)T
|
Command output was updated to show Hot Standby Router Protocol (HSRP) for IPv6 information.
|
12.2(33)SRA
|
This command was integrated into Cisco IOS Release 12.2(33)SRA.
|
12.2(33)SXH
|
This command was integrated into Cisco IOS Release 12.2(33)SXH.
|
Cisco IOS XE Release 2.1
|
This command was introduced on Cisco ASR 1000 series devices.
|
12.4(24)T
|
Command output was updated to show the Dynamic Host Configuration Protocol (DHCP) originated addresses.
|
12.2(50)SY
|
This command was integrated into Cisco IOS Release 12.2(50)SY.
|
15.0(1)SY
|
This command was integrated into Cisco IOS Release 15.0(1)SY.
|
15.2(2)SNG
|
This command was implemented on the Cisco ASR 901 Series Aggregation Services devices.
|
15.3(1)S
|
This command was integrated into Cisco IOS Release 15.3(1)S.
|
Cisco IOS XE Release 3.2SE
|
This command was integrated into Cisco IOS XE Release 3.2SE.
|
15.2(2)SA2
|
This command was implemented on the Cisco ME 2600X Series Ethernet Access Switches.
|
Usage Guidelines
The
show
ipv6
interface command provides output similar to the show ip interface command, except that it is IPv6-specific.
Use the
show
ipv6
interface command to validate the IPv6 status of an interface and its configured addresses. The show ipv6 interface command also displays
the parameters that IPv6 is using for operation on this interface and any configured features.
If the interface’s hardware is usable, the interface is marked up. If the interface can provide two-way communication for
IPv6, the line protocol is marked up.
If you specify an optional interface type and number, the command displays information only about that specific interface.
For a specific interface, you can enter the prefix keyword to see the IPv6 neighbor discovery (ND) prefixes that are configured
on the interface.
Examples
The
show
ipv6
interface command displays information about the specified interface.
Device(config)# show ipv6 interface ethernet0/0
Ethernet0/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::A8BB:CCFF:FE00:6700
No Virtual link-local address(es):
Global unicast address(es):
2001::1, subnet is 2001::/64 [DUP]
2001::A8BB:CCFF:FE00:6700, subnet is 2001::/64 [EUI]
2001:100::1, subnet is 2001:100::/64
Joined group address(es):
FF02::1
FF02::2
FF02::1:FF00:1
FF02::1:FF00:6700
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds (using 30000)
ND advertised reachable time is 0 (unspecified)
ND advertised retransmit interval is 0 (unspecified)
ND router advertisements are sent every 200 seconds
ND router advertisements live for 1800 seconds
ND advertised default router preference is Medium
Hosts use stateless autoconfig for addresses.
The table below describes the significant fields shown in the display.
Table 31. show ipv6 interface Field Descriptions
Field
|
Description
|
Ethernet0/0 is up, line protocol is up
|
Indicates whether the interface hardware is 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, down (down is not shown in sample output)
|
Indicates whether the software processes that handle the line protocol consider the line usable (that is, whether keepalives
are successful or IPv6 CP has been negotiated). 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.
|
Global unicast address(es):
|
Displays the global unicast addresses assigned to the interface.
|
Joined group address(es):
|
Indicates the multicast groups to which this interface belongs.
|
MTU
|
Maximum transmission unit of the interface.
|
ICMP error messages
|
Specifies the minimum interval (in milliseconds) between error messages sent on this interface.
|
ICMP redirects
|
The state of Internet Control Message Protocol (ICMP) IPv6 redirect messages on the interface (the sending of the messages
is enabled or disabled).
|
ND DAD
|
The 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.
|
ND advertised reachable time
|
Displays the neighbor discovery reachable time (in milliseconds) advertised on this interface.
|
ND advertised retransmit interval
|
Displays the neighbor discovery retransmit interval (in milliseconds) advertised on this interface.
|
ND router advertisements
|
Specifies the interval (in seconds) for neighbor discovery router advertisements (RAs) sent on this interface and the amount
of time before the advertisements expire.
As of Cisco IOS Release 12.4(2)T, this field displays the default router preference (DRP) value sent by this device on this
interface.
|
ND advertised default router preference is Medium
|
The DRP for the device on a specific interface.
|
Examples
The
show
ipv6
interface command displays information about attributes that may be associated with an IPv6 address assigned to the interface.
Attribute
|
Description
|
ANY
|
Anycast. The address is an anycast address, as specified when configured using the
ipv6 address command.
|
CAL
|
Calendar. The address is timed and has valid and preferred lifetimes.
|
DEP
|
Deprecated. The timed address is deprecated.
|
DUP
|
Duplicate. The address is a duplicate, as determined by duplicate address detection (DAD). To re-attampt DAD, the user must
use the
shutdown or
no shutdown command on the interface.
|
EUI
|
EUI-64 based. The address was generated using EUI-64.
|
OFF
|
Offlink. The address is offlink.
|
OOD
|
Overly optimistic DAD. DAD will not be performed for this address. This attribute applies to virtual addresses.
|
PRE
|
Preferred. The timed address is preferred.
|
TEN
|
Tentative. The address is in a tentative state per DAD.
|
UNA
|
Unactivated. The virtual address is not active and is in a standby state.
|
VIRT
|
Virtual. The address is virtual and is managed by HSRP, VRRP, or GLBP.
|
The following is sample output from the
show
ipv6
interface command when entered with the
brief keyword:
Device# show ipv6 interface brief
Ethernet0 is up, line protocol is up
Ethernet0 [up/up]
unassigned
Ethernet1 [up/up]
2001:0DB8:1000:/29
Ethernet2 [up/up]
2001:0DB8:2000:/29
Ethernet3 [up/up]
2001:0DB8:3000:/29
Ethernet4 [up/down]
2001:0DB8:4000:/29
Ethernet5 [administratively down/down]
2001:123::210:7BFF:FEC2:ACD8
Interface Status IPv6 Address
Ethernet0 up 3FFE:C00:0:1:260:3EFF:FE11:6770
Ethernet1 up unassigned
Fddi0 up 3FFE:C00:0:2:260:3EFF:FE11:6772
Serial0 administratively down unassigned
Serial1 administratively down unassigned
Serial2 administratively down unassigned
Serial3 administratively down unassigned
Tunnel0 up unnumbered (Ethernet0)
Tunnel1 up 3FFE:700:20:1::12
Examples
This sample output shows the characteristics of an interface that has generated a prefix from a local IPv6 prefix pool:
Device# show ipv6 interface Ethernet 0/0 prefix
interface Ethernet0/0
ipv6 address 2001:0DB8::1/64
ipv6 address 2001:0DB8::2/64
ipv6 nd prefix 2001:0DB8:2::/64
ipv6 nd prefix 2001:0DB8:3::/64 2592000 604800 off-link
end
.
.
.
IPv6 Prefix Advertisements Ethernet0/0
Codes: A - Address, P - Prefix-Advertisement, O - Pool
U - Per-user prefix, D - Default
N - Not advertised, C - Calendar
default [LA] Valid lifetime 2592000, preferred lifetime 604800
AD 2001:0DB8:1::/64 [LA] Valid lifetime 2592000, preferred lifetime 604800
APD 2001:0DB8:2::/64 [LA] Valid lifetime 2592000, preferred lifetime 604800
P 2001:0DB8:3::/64 [A] Valid lifetime 2592000, preferred lifetime 604800
The default prefix shows the parameters that are configured using the ipv6 nd prefix default command.
Examples
This sample output shows the state of the DRP preference value as advertised by this device through an interface:
Device# show ipv6 interface gigabitethernet 0/1
GigabitEthernet0/1 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::130
Description: Management network (dual stack)
Global unicast address(es):
FEC0:240:104:1000::130, subnet is FEC0:240:104:1000::/64
Joined group address(es):
FF02::1
FF02::2
FF02::1:FF00:130
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds
ND advertised 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
ND advertised default router preference is Low
Hosts use stateless autoconfig for addresses.
Examples
When HSRP IPv6 is first configured on an interface, the interface IPv6 link-local address is marked unactive (UNA) because
it is no longer advertised, and the HSRP IPv6 virtual link-local address is added to the virtual link-local address list with
the UNA and tentative DAD (TEN) attributes set. The interface is also programmed to listen for the HSRP IPv6 multicast address.
This sample output shows the status of UNA and TEN attributes, when HSRP IPv6 is configured on an interface:
Device# show ipv6 interface ethernet 0/0
Ethernet0/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80:2::2 [UNA]
Virtual link-local address(es):
FE80::205:73FF:FEA0:1 [UNA/TEN]
Global unicast address(es):
2001:2::2, subnet is 2001:2::/64
Joined group address(es):
FF02::1
FF02::2
FF02::66
FF02::1:FF00:2
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ND DAD is enabled, number of DAD attempts: 1
After the HSRP group becomes active, the UNA and TEN attributes are cleared, and the overly optimistic DAD (OOD) attribute
is set. The solicited node multicast address for the HSRP virtual IPv6 address is also added to the interface.
This sample output shows the status of UNA, TEN and OOD attributes, when HSRP group is activated:
Device# show ipv6 interface ethernet 0/0
Ethernet0/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80:2::2 [UNA]
Virtual link-local address(es):
FE80::205:73FF:FEA0:1 [OPT]
Global unicast address(es):
2001:2::2, subnet is 2001:2::/64
Joined group address(es):
FF02::1
FF02::2
FF02::66
FF02::1:FF00:2
FF02::1:FFA0:1
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ND DAD is enabled, number of DAD attempts: 1
The table below describes additional significant fields shown in the displays for the
show
ipv6
interface command with HSRP configured.
Table 32. show ipv6 interface Command with HSRP Configured Field Descriptions
Field
|
Description
|
IPv6 is enabled, link-local address is FE80:2::2 [UNA]
|
The interface IPv6 link-local address is marked UNA because it is no longer advertised.
|
FE80::205:73FF:FEA0:1 [UNA/TEN]
|
The virtual link-local address list with the UNA and TEN attributes set.
|
FF02::66
|
HSRP IPv6 multicast address.
|
FE80::205:73FF:FEA0:1 [OPT]
|
HSRP becomes active, and the HSRP virtual address marked OPT.
|
FF02::1:FFA0:1
|
HSRP solicited node multicast address.
|
Examples
When you enable Mobile IPv6 on an interface, you can configure a minimum interval between IPv6 router advertisement (RA)
transmissions. The
show
ipv6
interface command output reports the minimum RA interval, when configured. If the minimum RA interval is not explicitly configured,
then it is not displayed.
In the following example, the maximum RA interval is configured as 100 seconds, and the minimum RA interval is configured
as 60 seconds on Ethernet interface 1/0:
Device(config-if)# ipv6 nd ra-interval 100 60
Subsequent use of the
show
ipv6
interface then displays the interval as follows:
Device(config)# show ipv6 interface ethernet 1/0
Ethernet1/0 is administratively down, line protocol is down
IPv6 is enabled, link-local address is FE80::A8BB:CCFF:FE00:5A01 [TEN]
No Virtual link-local address(es):
No global unicast address is configured
Joined group address(es):
FF02::1
FF02::2
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds
ND advertised reachable time is 0 milliseconds
ND advertised retransmit interval is 0 milliseconds
ND router advertisements are sent every 60 to 100 seconds
ND router advertisements live for 1800 seconds
ND advertised default router preference is Medium
Hosts use stateless autoconfig for addresses.
In the following example, the maximum RA interval is configured as 100 milliseconds (ms), and the minimum RA interval is
configured as 60 ms on Ethernet interface 1/0:
Device(config)# show ipv6 interface ethernet 1/0
Ethernet1/0 is administratively down, line protocol is down
IPv6 is enabled, link-local address is FE80::A8BB:CCFF:FE00:5A01 [TEN]
No Virtual link-local address(es):
No global unicast address is configured
Joined group address(es):
FF02::1
FF02::2
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds
ND advertised reachable time is 0 milliseconds
ND advertised retransmit interval is 0 milliseconds
ND router advertisements are sent every 60 to 100 milliseconds
ND router advertisements live for 1800 seconds
ND advertised default router preference is Medium
Hosts use stateless autoconfig for addresses.
The table below describes additional significant fields shown in the displays for the
show
ipv6
interface command with minimum RA interval information configured.
Table 33. show ipv6 interface Command with Minimum RA Interval Information Configuration Field Descriptions
Field
|
Description
|
ND router advertisements are sent every 60 to 100 seconds
|
ND RAs are sent at an interval randomly selected from a value between the minimum and maximum values. In this example, the
minimum value is 60 seconds, and the maximum value is 100 seconds.
|
ND router advertisements are sent every 60 to 100 milliseconds
|
ND RAs are sent at an interval randomly selected from a value between the minimum and maximum values. In this example, the
minimum value is 60 ms, and the maximum value is 100 ms.
|