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    Monitoring Static or Dynamic Entries of the IPv6 Neighbor Discovery Cache


    Display IPv6 Neighbor Discovery cache information static entries, dynamic entries, or both:

    • You can use the static keyword to display only static entries
    • You can use the dynamic keyword to display only dynamic entries
    • You can use the summary keyword to display summary information


    • You must configure an IPv6 license using the license ipv6 command before using the IPv6 routing protocol configuration commands on the E Series router.
    • All IPv6 routing protocol-related configurations are removed from the virtual router when you issue the no ipv6 command.


    To display both static and dynamic entries from the IPv6 Neighbor Discovery cache:

    host1# show ipv6 neighbors
       Interface         IPv6-Address    Type   Hardware Addr  State  Age 
    ----------------- ----------------- ------- -------------- ----- -----
    FastEthernet4/1        1::1          dynamic 0090.1a40.05e5 reach 3 

    To display summary information of both static and dynamic entries from the IPv6 Neighbor Discovery cache:

    host1# show ipv6 neighbors summary
    Total IPv6 neighbors: 7
    By type: 5 global, 2 link-local, 0 anycast, 0 unknown
    By state: 5 reachable, 0 incomplete, 2 stale, 0 probe, 0 delay, 0 init
    IPv6 address conflicts: 0 during DAD resolution, 0 after DAD resolution


    Table 1 lists the show ipv6 neighbors command output fields.

    Table 1: show ipv6 neighbors Output Fields

    Field Name

    Field Description


    Neighbor interface


    IPv6 address for the interface


    Type of interface (dynamic, static)

    Hardware Addr

    Layer 2 address of the interface


    State of the interface (delay, incomplete, probe, reachable, stale)


    Amount of time (in seconds) since the router contacted the neighbor

    Total IPv6 neighbors

    Total number of IPv6 neighbors

    By type

    List by neighbor type (global, link-local, anycast, and unknown)

    By state

    List by neighbor state (reachable, incomplete, stale, probe, delay, an init)

    IPv6 address conflicts

    Number of conflicts during or after duplicate address detection resolution

    Published: 2014-08-13