[c-nsp] IGMP on 6500s - %MCAST-xx-GC_LIMIT_EXCEEDED

[Dale W. Carder]

On Sep 11, 2006, at 11:16 AM, Phil Mayers wrote:
> Tim Stevenson wrote:
>> It refers to Layer 2 group MAC entries (try sh mac- mul ig or sh
>> multicast group); these are driven by IGMP join activity in host  
>> VLANs.
> What else can I do
...
> to try and diagnose the source?
> Debug of IGMP join activity is unlikely to be do-able on this router.


You can monitor igmp activity via SNMP.

John Kristoff wrote a nice tool called mcastsum[*] to do basic polling
of multicast related counters to aid troubleshooting.

You can download mcastsum w/ my patch to prettify the output at:
http://net.doit.wisc.edu/~dwcarder/scripts/

Dale

----------------------------------
Dale W. Carder - Network Engineer
University of Wisconsin at Madison
http://net.doit.wisc.edu/~dwcarder

[*]  The original can be found at http://aharp.ittns.northwestern.edu/ 
software/