[c-nsp] router does not see IGMP joins

[Victor Sudakov]

Colleagues,

What could be the reason that a Cisco 1841 router (IOS 12.4(13r)T)
does not see IGMP joins to a particular group? tcpdump shows that the
joins are being sent to the network, however "debug ip igmp 224.0.1.3"
does not show them.

Here is the packet dump: http://zalil.ru/32803276
and the configuration:


kedrovy#sh ip igmp interface fastEthernet 0/0
FastEthernet0/0 is up, line protocol is up
  Internet address is 10.14.128.129/26
  IGMP is enabled on interface
  Current IGMP host version is 2
  Current IGMP router version is 2
  IGMP query interval is 60 seconds
  IGMP querier timeout is 120 seconds
  IGMP max query response time is 10 seconds
  Last member query count is 2
  Last member query response interval is 1000 ms
  Inbound IGMP access group is not set
  IGMP activity: 8 joins, 6 leaves
  Multicast routing is enabled on interface
  Multicast TTL threshold is 0
  Multicast designated router (DR) is 10.14.128.129 (this system)
  IGMP querying router is 10.14.128.129 (this system)
  Multicast groups joined by this system (number of users):
      224.0.1.40(1)  224.0.1.1(1)
kedrovy#

I can forcibly join the interface to the 224.0.1.3 group and then the
traffic begins to flow:

kedrovy(config-if)#ip igmp join-group 224.0.1.3
kedrovy(config-if)#^Z
kedrovy#
1w2d: IGMP(0): WAVL Insert group: 224.0.1.3 interface: FastEthernet0/0Successful
1w2d: IGMP(0): Send v2 Report for 224.0.1.3 on FastEthernet0/0
1w2d: IGMP(0): Received v2 Report on FastEthernet0/0 from 10.14.128.129 for 224.0.1.3
1w2d: IGMP(0): Received Group record for group 224.0.1.3, mode 2 from 10.14.128.129 for 0 sources
1w2d: IGMP(0): Switching to EXCLUDE mode for 224.0.1.3 on FastEthernet0/0
1w2d: IGMP(0): Updating EXCLUDE group timer for 224.0.1.3
1w2d: IGMP(0): MRT Add/Update FastEthernet0/0 for (*,224.0.1.3) by 0
1w2d: IGMP(0): MRT Add/Update FastEthernet0/0 for (*,224.0.1.3) by 4
1w2d: %SYS-5-CONFIG_I: Configured from console by vty0 (10.14.134.125)
kedrovy#
1w2d: IGMP(0): Send v2 general Query on FastEthernet0/0
1w2d: IGMP(0): Set report delay time to 2.8 seconds for 224.0.1.3 on FastEthernet0/0
1w2d: IGMP(0): Send v2 general Query on FastEthernet0/1
kedrovy#
1w2d: IGMP(0): Send v2 Report for 224.0.1.3 on FastEthernet0/0
1w2d: IGMP(0): Received v2 Report on FastEthernet0/0 from 10.14.128.129 for 224.0.1.3
1w2d: IGMP(0): Received Group record for group 224.0.1.3, mode 2 from 10.14.128.129 for 0 sources
1w2d: IGMP(0): Updating EXCLUDE group timer for 224.0.1.3
1w2d: IGMP(0): MRT Add/Update FastEthernet0/0 for (*,224.0.1.3) by 0

-- 
Victor Sudakov,  VAS4-RIPE, VAS47-RIPN
sip:sudakov at sibptus.tomsk.ru