[Xorp-users] Problem in IGMP

[Pavlin Radoslavov]

> I am using xorp-1.1 on linux and trying use Xorp Router for
> PIM-SM.Following is my topology
> =0D
> ---------                      -------                        ------
> |  H1 | e0 ----------- e2 |  R1 | e1--------------e1| R2 |
> ---------                       ------                        ------
> =0D
> H1 -- IGMP Host (Group member)
> =0D
> R1 - XORP Router (PIM)
> R2- XORP Router (PIM)=0D
> =0D
> Basically I wanted R1 to send PIM join message to R2 after receiving
> IGMP join message from H1
> =0D
> I am facing following problems
> 1.When Host H1 sends IGMP v2 Report message, Xorp router R1 is not able
> receive that packet and hence make an entry in its IGMP group table.
> =0D
> I would like to know, anybody has tried this one out.is anything wrong
> with Configuration.

Your configuration looks fine, except that you may want to add
fib2mrib to it (though it is not mandatory and is not related to the
problem you have).

The real problem is that somehow in your IGMP reports from Host H1
the included address is 240.1.0.1.
However, 240.1.0.1 is NOT a multicast address, hence XORP eventually
is dropping it. You may see warning messages like:

    "RX %s from %s to %s on vif %s: the group address %s is not "
    "valid multicast address"

If you don't see such warning messages, then probably the kernel
itself is dropping them (e.g., the FreeBSD kernel should drop them;
probably the same should happen with Linux).

Please use a real multicast address in the range 224.x.x.x-239.x.x.x
and try again. Just curious, how did you manage to generate this
bogus IGMP report message?

Pavlin


> When I do tcpdum on R1's e2 interface I am able to receive the packet,
> However Xorp Router is not receiving the same !
> sudheer]# tcpdump -i eth2
> eth2: Promiscuous mode enabled.
> tcpdump: listening on eth2
> 18:21:06.256636 20.10.10.30 > 224.0.0.1: igmp v2 report 240.1.0.1 [ttl
> 1] ----> This is sent by Host H1
> 18:21:06.280004 20.10.10.30 > 224.0.0.1: igmp v2 report 240.1.0.2 [ttl
> 1] ---- >This is sent by Host H1
> 18:21:20.166912 20.10.10.10 > 224.0.0.13: pim v2 Hello (Hold-time 1m45s)
> (DR-Priority: 1) (Genid: 0x1401d29c) [tos 0xc0]  [ttl 1]
> 18:21:24.636608 20.10.10.10 > 224.0.0.1: igmp query v2 [tos 0xc0]  [ttl
> 1]
> 18:21:28.462125 20.10.10.10 > 224.0.0.2: igmp v2 report 224.0.0.2 (DF)
> [ttl 1]
> 18:21:32.372205 20.10.10.10 > 224.0.0.13: igmp v2 report 224.0.0.13 (DF)
> [ttl 1]
> =0D
> I have attached show outputs and config files on R1 and R2