Re: Multicast Loopback strange behaviour

Checkout with "debug ip mpacket" to see wat exactly u r sending to the
destination......
Also use "mstat" and "mtrace" commands for further information......

On Tue, Dec 1, 2009 at 1:26 PM, <nrafia_at_gmail.com> wrote:
> Hi GS,
>
> i have configured few routers in series Aluminum-->Platinum -->Brass (RP)
> -->TIN -->Iron (Jeff-vol-2 chapter 5,page:505). On Aluminum i have
> configured one l0 ip add 172.16.1.1 255.255.255.0 instead of attaching host.
>
> when i ping 236.82.134.23 (iron multicast group joined by loopback). i got
> following output...
>
> Aluminum#ping 236.82.134.23 rep 3
>
> Type escape sequence to abort.
> Sending 3, 100-byte ICMP Echos to 236.82.134.23, timeout is 2 seconds:
>
> Reply to request 0 from 172.16.2.241, 20 ms
> Reply to request 0 from 172.16.2.241, 24 ms
> Reply to request 1 from 172.16.2.241, 12 ms
> Reply to request 1 from 172.16.2.241, 16 ms
> Reply to request 2 from 172.16.2.241, 8 ms
> Reply to request 2 from 172.16.2.241, 12 ms
>
> why i am getting duplicate replies?
>
>
> second sh ip mroute on Aluminum (ping originator) shows
>
> Aluminum#sh ip mroute
> IP Multicast Routing Table
> Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
> L - Local, P - Pruned, R - RP-bit set, F - Register flag,
> T - SPT-bit set, J - Join SPT, M - MSDP created entry,
> X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
> U - URD, I - Received Source Specific Host Report,
> Z - Multicast Tunnel, z - MDT-data group sender,
> Y - Joined MDT-data group, y - Sending to MDT-data group
> Outgoing interface flags: H - Hardware switched, A - Assert winner
> Timers: Uptime/Expires
> Interface state: Interface, Next-Hop or VCD, State/Mode
>
> (*, 236.82.134.23), 00:02:08/stopped, RP 172.16.224.1, flags: SPF
> Incoming interface: Serial1/0, RPF nbr 172.16.2.234
> Outgoing interface list: Null
>
> (172.16.1.1, 236.82.134.23), 00:02:08/00:03:21, flags: FT
> Incoming interface: Loopback0, RPF nbr 0.0.0.0
> Outgoing interface list:
> Serial1/0, Forward/Sparse, 00:01:48/00:02:40
>
> (*, 224.0.1.40), 00:02:11/00:02:19, RP 172.16.224.1, flags: SJCL
> Incoming interface: Serial1/0, RPF nbr 172.16.2.234
> Outgoing interface list:
> Loopback0, Forward/Sparse, 00:02:11/00:02:19
>
> all other routers shows
>
> Iron#sh ip mroute
> IP Multicast Routing Table
> Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
> L - Local, P - Pruned, R - RP-bit set, F - Register flag,
> T - SPT-bit set, J - Join SPT, M - MSDP created entry,
> X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
> U - URD, I - Received Source Specific Host Report,
> Z - Multicast Tunnel, z - MDT-data group sender,
> Y - Joined MDT-data group, y - Sending to MDT-data group
> Outgoing interface flags: H - Hardware switched, A - Assert winner
> Timers: Uptime/Expires
> Interface state: Interface, Next-Hop or VCD, State/Mode
>
> (*, 236.82.134.23), 00:09:04/stopped, RP 172.16.224.1, flags: SJCL
> Incoming interface: Serial1/0, RPF nbr 172.16.2.242
> Outgoing interface list:
> Loopback0, Forward/Sparse, 00:09:04/00:02:46
>
> (172.16.2.233, 236.82.134.23), 00:06:34/00:02:52, flags: LJT
> Incoming interface: Serial1/0, RPF nbr 172.16.2.242
> Outgoing interface list:
> Loopback0, Forward/Sparse, 00:06:34/00:02:46
>
> (172.16.1.1, 236.82.134.23), 00:06:34/00:02:52, flags: LJT
> Incoming interface: Serial1/0, RPF nbr 172.16.2.242
> Outgoing interface list:
> Loopback0, Forward/Sparse, 00:06:34/00:02:46
>
> (*, 224.0.1.40), 00:09:04/00:02:49, RP 172.16.224.1, flags: SJCL
> Incoming interface: Serial1/0, RPF nbr 172.16.2.242
> Outgoing interface list:
> Loopback0, Forward/Sparse, 00:09:04/00:02:49
>
> my second question. why on originator its mapping to loopback 172.16.1.1,
> instead of serial interface? and why on all the rest of the routers i can
> see two mapping, one for loopback and one for serial?
>
> Thanks in advance for any help.
>
>
> Best Regards,
>
> Nadeem Rafi
>
>
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Received on Tue Dec 01 2009 - 17:05:07 ART