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Forum Replies

  1. Hi Rene,

    I think that it is a errata:

    This prefix-list checks the entire 2001::/16 range and permits subnets with a /64 or larger.
    It should be:

    This prefix-list checks the entire 2001::/16 range and permits subnets with a /64 o smaller

    Thanks you

  2. Hi Diego,

    Thanks for the message, this sentence is correct though. Take a look at the prefix-list:

    ipv6 prefix-list SMALL_NETWORKS permit 2001::/16 le 64

    The “le 64” part means that it will match /64, /63, /62, /61, /60, etc. All of these are “larger” subnets than /64.


  3. Hi Diana,

    I’d have to test this to confirm it but when you configure it under the main BGP process then it only applies to the IPv4 address family, even though you can establish a neighbor adjacency through IPv6.

    The IPv6 address family is where you configure everything…including route-maps.

    If you want to confirm this, you can advertise some IPv4 prefixes…see if the route-map matches your IPv4 routes. I think it will.


  4. Cisco documentation from 2016 provides different order for outbound filtering:

    For inbound updates the order of preference is:
    prefix-list, distribute-list

    For outbound updates the order of preference is:

    route-map | unsuppress-map
    advertise-map (conditional-advertisement)
    ORF prefix-list (a prefix-list the neighbor sends us)


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