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IPv6Privileged EXEC

show ipv6 interface brief

Displays a summary of IPv6 interface status and addresses, useful for quickly verifying IPv6 configuration and interface operational state.

Syntax·Privileged EXEC
show ipv6 interface brief

When to Use This Command

  • Quickly verify which interfaces have IPv6 enabled and their configured addresses after initial setup.
  • Troubleshoot why an interface is not showing an IPv6 address or is administratively down.
  • Check if an interface has obtained a link-local address automatically.
  • Audit IPv6 addressing across multiple routers in a network.

Command Examples

Basic IPv6 interface brief output

show ipv6 interface brief
GigabitEthernet0/0        [up/up]    FE80::1
    Global unicast: 2001:DB8:1::1
GigabitEthernet0/1        [up/up]    FE80::2
    Global unicast: 2001:DB8:2::1
Serial0/0/0               [up/up]    FE80::3
    Global unicast: 2001:DB8:3::1
Loopback0                 [up/up]    FE80::4
    Global unicast: 2001:DB8:0::1

Each line shows interface name, status in brackets (line protocol/operational), link-local address, and any global unicast addresses. 'up/up' means both line protocol and interface are operational. 'down/down' indicates a problem.

Interface with no IPv6 address configured

show ipv6 interface brief
GigabitEthernet0/0        [up/up]    unassigned
GigabitEthernet0/1        [up/up]    FE80::1
    Global unicast: 2001:DB8:1::1
Serial0/0/0               [administratively down/down] unassigned

GigabitEthernet0/0 is up but has no IPv6 address (unassigned). Serial0/0/0 is administratively down (shutdown command applied). The link-local address is missing when no IPv6 is enabled.

Understanding the Output

The output lists each interface with its status in brackets: first field is line protocol (up/down), second is interface operational status (up/down). 'administratively down' means the interface is manually disabled. The link-local address (FE80::/10) is automatically generated when IPv6 is enabled. If 'unassigned' appears, no IPv6 address is configured. Global unicast addresses are shown indented below the interface line. In a real network, look for 'up/up' for healthy interfaces; 'down/down' or 'administratively down' indicates issues. Missing link-local address suggests IPv6 is not enabled on that interface.

CCNA Exam Tips

1.

CCNA exam may ask which command verifies IPv6 interface status; 'show ipv6 interface brief' is the quickest.

2.

Remember that link-local addresses are automatically assigned when IPv6 is enabled, even without a global address.

3.

The status format [protocol/operational] is the same as IPv4 'show ip interface brief'.

4.

An interface with 'up/up' but 'unassigned' means IPv6 is enabled but no global address configured.

Common Mistakes

Confusing 'show ipv6 interface brief' with 'show ip interface brief' — the former is for IPv6, the latter for IPv4.

Assuming 'unassigned' means IPv6 is disabled; it only means no address is configured, but IPv6 may still be enabled.

Overlooking the link-local address; it is always present when IPv6 is enabled and can be used for neighbor discovery.

Related Commands

show ip interface brief

Displays a summary of all IP interfaces on the device, including their IP address, status, and protocol state, used for quick verification of interface configuration and connectivity.

show ipv6 route

Displays the IPv6 routing table on a Cisco router, showing all known IPv6 routes and their next-hop information for troubleshooting and verification of IPv6 routing.

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