Re: Multicast Routing Issue

The oif-null message basically means there is something wrong with the
IGMP membership or Multicast routing as the router is receiving
packets, but doesn't know what to do with it. Just know how it needs
to work and debug your config.

-- 
Regards,
Rick Mur
CCIE2 #21946 (R&S / Service Provider)
Juniper JNCIA-ER & JNCIA-EX
MCSA:Messaging, MCSE
Sr. Support Engineer  IPexpert, Inc.
URL: http://www.IPexpert.com
On 3 aug 2009, at 12:28, Federico Cossu wrote:
> the "oif-null" multicast troubleshooting is the one i hate,
> imho it's really difficult to debug this, i prefer to found myself in
> the "RPF-like" problems.
>
> /R
>
>
> 2009/8/3 Joe Astorino <jastorino_at_ipexpert.com>:
>> Try a "debug ip mpacket" on that device and see what you can find  
>> out.  That
>> will help diagnose the problem.
>>
>> On Fri, Jul 31, 2009 at 11:53 AM, <quinton_at_flowtraders.com> wrote:
>>
>>> Morning All,
>>>
>>> I am trying to determine why a PIM-SM RP is pruning a m/cast group  
>>> from the
>>> m/cast routing table. PIM neighbor relationships are established  
>>> and there
>>> is
>>> no problem with RPF. I have the following output from "sh ip mroute
>>> 239.33.42.1
>>> count.
>>>
>>> pcoresw01#sh ip mroute 239.33.42.1 count
>>> IP Multicast Statistics
>>> 7 routes using 3826 bytes of memory
>>> 6 groups, 0.16 average sources per group
>>> Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kilobits  
>>> per
>>> second
>>> Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc)
>>>
>>> Group: 239.33.42.1, Source count: 1, Packets forwarded: 0, Packets
>>> received:
>>> 70758
>>> RP-tree: Forwarding: 0/0/0/0, Other: 67595/0/67595
>>> Source: 10.33.42.134/32, Forwarding: 0/-1/0/0, Other: 3163/0/3163
>>>
>>> AND
>>>
>>> pcoresw01#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
>>> 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
>>>
>>> (*, 239.33.42.1), 1d06h/stopped, RP 10.254.254.9, flags: SP
>>> Incoming interface: Null, RPF nbr 0.0.0.0
>>> Outgoing interface list: Null
>>>
>>> (10.33.42.134, 239.33.42.1), 02:22:33/00:02:53, flags: PT
>>> Incoming interface: Vlan42, RPF nbr 0.0.0.0, RPF-MFD
>>> Outgoing interface list: Null
>>>
>>> My question is this: what does the Other: 3163/0/3163 represent. I
>>> understand
>>> that these are multicast packet which have been dropped but I need  
>>> to find
>>> out
>>> why the drops occurred.
>>>
>>> Many thanks
>>>
>>> Quinton
>>>
>>>
>>> Blogs and organic groups at http://www.ccie.net
>>>
>>> _______________________________________________________________________
>>> Subscription information may be found at:
>>> http://www.groupstudy.com/list/CCIELab.html
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>> --
>> Regards,
>>
>> Joe Astorino - CCIE #24347 R&S
>> Technical Instructor - IPexpert, Inc.
>> Cell: +1.586.212.6107
>> Fax: +1.810.454.0130
>> Mailto:  jastorino_at_ipexpert.com
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
> -- 
> Faeddare pagu, sabidorla meda.
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
Blogs and organic groups at http://www.ccie.net