Cisco 2821 15.1.3(T4) Multicast Tun0 int not formed for second VRF

Discussion in 'Networking & Security' started by /dev/null, Oct 17, 2019.

  1. /dev/null

    /dev/null [H]ardForum Junkie

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    Hey Guys,

    I have a Cisoc 2821 (rescued from the garbage) in my lab with 2 physical interfaces. We'll call this router "P"

    Each physical interface on router "P" has no config, but has 3 802.1q under it and is plugged into a switch that allows trunking to these vlans. All BGP/routing/unicast works as expected between router "P" (simulated provider) and router "E" (simulated customer - our on-site router)

    On router P (interfaces Gi0/0, and Gi0/1)

    Gi0/0 has no config but Gi 0/0.1, Gi0/0.2, Gi0/0.3 all have config and are assigned to vrf "c"
    Gi0/1 also has no config but Gi0/1.4, Gi0/0.5, Gi0/0.6 all have config & are assigned to vrf "s"

    I've got these 2 vrfs to emulate 2 provider networks. Both vrfs run BGP & multicast (pim sparse mode, with autorp)

    Gi0/0.1 goes to router E and does BGP
    Gi0/1.4 also goes to router E and does BGP

    As far as router E is concerned, it's talking to 2 different networks.

    Multicast routing is turned on for both vrfs (Router P) & config is the same for both. Auto RP is also enabled as is pim-sparse mode for both interfaces on router E as well as router P.

    vrf c works great & it finds the RP.
    vrf s never finds an RP.

    I've shut down the working vrf c parent interface (Gi0/0) just incase it was some RPF bug or something, but it still doesn't work.

    Anyone seen this? I'm almost convinced this is a bug...
     
    Last edited: Oct 17, 2019
  2. Ehren8879

    Ehren8879 [H]ardness Supreme

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    I would recommend posting this on /r/networking over on reddit.
     
  3. /dev/null

    /dev/null [H]ardForum Junkie

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    I'm going to give this a shot
     
  4. scrappymouse

    scrappymouse n00b

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    not sure of your IP scheme, but try "ping vrf <vrf instance> <ip address>" for both, and see if it's what you're expecting, also examine your routing tables "Show ip route vrf <vrf name>" and see if the routes are what you're expecting