All things related to multicast

[Brent Draney <>]

Turning on sap has been a useful way of finding what hop is
breaking multicast.  Forcing all hops to be multicast clients
and populate multicast is useful, SAP is not.

If someone has a better way ...

Brent
 
> 
> Michael, *: 
> 
>  a) If any of you have opened directly or indirectly a case with
>     the TAC, please tell us. I have Cc'ed the developer as well so
>     that we can take appropriate action.
>  
>  b) Without implying that it is the root cause for the problem seen,
>     the new error message you see was introduced via a recent
>     bugfix that tried to overcome an incompatibility of SAP
>     with other new SAP messages ;-((((. 
>     
>     If you have a CCO password, you can look up the description of
>     that issue at:
> 
>       
> http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCee92905&Submit=Search
>   
>  c) In general we recommend not to enable SAP, so i am very interested
>     to get a reinforcement about how useful this command still is
>     to common user practices ;-)) After all: 
>     There is really nothing in SAP that you could not do better by 
>     running SAP on a host system (PC, unix, linux,...).
> 
>     The router is just receiving these messages and you can display
>     them with "show" commands. Nothing else. The forwarding of SAP,
>     as already said by someone else on this thread is completely
>     unaffected.
> 
>     The problem obviously is that because SAP on the router is used
>     ONLY for such random "show" commands by few users, there is
>     no real business incentive to follow all the newest developments
>     into decoding new type of SAP messages, so the command also
>     becomes less and less useful - and it was only of limited use
>     in the beginning.
>   
> Thanks
>     Toerless
> 
> On Thu, Mar 23, 2006 at 04:21:07PM -0000, Michael Forrest wrote:
> > 
> > Has anyone seen the following issue with Cisco router running ipv4
> > multicast?
> > 
> > The log messages just seem to be full of the following msg:-
> > 
> > Mar 20 16:05:38 door.erg.abdn.ac.uk 299: *Mar 16 06:39:31.369 UTC:
> > %MROUTE-6-UNSUPPORTED_SAP_FORMAT: Received unsupported format SAP message
> > from (129.116.74.139)
> > 
> > The MFIB (multicast forwarding information base) seems to have a memory 
> > leak
> > and eventually consumes all the memory available on the router. The router
> > becomes inaccessible on the console and over the network and requires a
> > power cycle to recover. Although strangely enough, still seems to be
> > functional (if just unaccessible).
> > 
> > A show ver from the router yields (it's a Cisco 2621XM):-
> > 
> > Cisco IOS Software, C2600 Software (C2600-ADVENTERPRISEK9-M), Version
> > 12.4(7), RELEASE SOFTWARE (fc6)
> > Technical Support: http://www.cisco.com/techsupport
> > Copyright (c) 1986-2006 by Cisco Systems, Inc.
> > Compiled Tue 28-Feb-06 23:32 by alnguyen
> > 
> > Doing a show proc memory shows that it seems to consume about 1MB of 
> > memory
> > every 4-5hours until the router just falls over.
> > 
> > All the unsupported SAP messages come from a cluster of machines with
> > similar names to:-
> > 
> > vbrick-cma5136.communication.utexas.edu
> > 
> > Anyone had/solved this issue before?
> > 
> > -Michael
> > 
> > --
> > Michael Forrest,
> > Directorate of Information Systems and Services,
> > University of Aberdeen.
> > 
> > Tel: +44-1224-273392
> 
> -- 
> Thanks
>    Toerless Eckert
>    
>