Sec 5.1 Multicast Filtering

I missed this section because of something to do with frame-relay mappings and the output from show ip pim neighbors.  Same thing happend on Mock Lab 1.  I reloaded my configs and I'm not sure what this is about.   Anyone point me to some docs concerning PIM and FR mappings?

The question was just about rejecting joins to non auto-rp's, which is done with "ip pim accept-rp auto-rp".  Obviously I'm totally missing something here.

Here's some output from one of the FR routers

Rack26R1#sh ip pim int

Address          Interface                Ver/   Nbr    Query  DR     DR
                                          Mode   Count  Intvl  Prior      FastEthernet0/0          v2/SD  0      30     1      Serial0/0                v2/SD  1      30     1      Serial0/1                v2/SD  1      30     1

Rack26R1#sh ip pim neighbor
PIM Neighbor Table
Mode: B - Bidir Capable, DR - Designated Router, N - Default DR Priority,
      S - State Refresh Capable
Neighbor          Interface                Uptime/Expires    Ver   DR
Address                                                            Prio/Mode       Serial0/0                00:21:49/00:01:34 v2    1 / DR S       Serial0/1                00:22:47/00:01:34 v2    1 / S

Rack26R1#sh frame-relay map
Serial0/0 (up): ip dlci 102(0x66,0x1860), static,
              CISCO, status defined, active

Rack26R1#sh ip pim rp map
PIM Group-to-RP Mappings

  RP (?), v2v1
    Info source: (?), elected via Auto-RP
         Uptime: 00:22:28, expires: 00:02:26
  RP (?), v2v1
    Info source: (?), elected via Auto-RP
         Uptime: 00:22:40, expires: 00:02:27

Thanks in advance



  • Hi,

    the exact same thing happened to me. The lab book said that you 'need to ensure you don't have any PIM DR's with the IP address'. My understanding is that the DR IP is on point-to-point interfaces only. In a multi-access environment, a DR needs to be elected to decide which router will send PIM register messages to the RP and avoid duplication of multicast traffic. 

    So short of rebuilding the topology , I'm not sure how we can get rid of the addresses.

    Maybe someone from INE could explain the idea behind this statement? I couldn't find any clues in the SG.

    The actual task has nothing to do with this as far as I can tell.








  • Did you guys ever find the answer? I missed this question because of those neighbors. My guess is that we need to get rid of the FR mappings by issuing the "no frame-relay inverse-arp DLCI#" command per DLCI (except on the DLCI we're actually using) learned via LMI on each router.

  • The neighbor come from Inverse-ARP on frame-relay interface, regarding to the auto-install feature :).


    In order to get rid of those mapping, first off we have to configure the frame relay interface to disable the inverse-arp and arp frame. second make sure we've rebooted our routers to make sure the configuration change was in effect.


    hopefully can help a little bit :)

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