Subject: [magma] IGMP Router Group Membership state

From: rajasekar bonthala <[email-masked]>
Date: Mon, 18 Jan 2010 16:30:39 +0530

Hi All,

Section 6.4.2 of RFC 3376 talks about on how should IGMP routers respond on
receiving Filter Mode Change and Source List Change records.

I do not get about what should be the action of the IGMP router in the
following scenario.

Router is in "INCLUDE A"  state. It receives a report "TO EXCLUDE A". Here,
IGMP Router sends a Group and Source specific query for the source A group
B.

Let us say that IGMP Router receives a response "IS INCLUDE A".

What should be the state of the IGMP Router before and after receiving
response?
What should be the state of the IGMP Router if it doesn't receive any
response before the last member query time expires?

In my IGMP Router I could see the state as below :

BEFORE RESPONSE :

atca-f120#show ip igmp groups detail
Interface:      ge45
Group:          224.0.6.130
Uptime:         00:00:20
Group mode:     Exclude (Expires: 00:06:22)
Last reporter:  192.168.1.8
Group source list: (R - Remote, M - SSM Mapping, S - Static)
Include Source List :
  Source Address  Uptime    v3 Exp    Fwd  Flags
  10.10.10.10     00:00:20  00:00:27  Yes  R

NO RESPONSE :

atca-f120#show ip igmp groups detail
Interface:      ge45
Group:          224.0.6.130
Uptime:         00:00:49
Group mode:     Exclude (Expires: 00:05:53)
Last reporter:  192.168.1.8
Group source list: (R - Remote, M - SSM Mapping, S - Static)
Exclude Source List :
  Source Address  Uptime    v3 Exp    Fwd  Flags
  10.10.10.10     00:00:49  stopped   No   R

But could not interpret the above outputs. Can anyone help me.

Thanks,
RajaSekhar