All things related to multicast

[Bill Owens <>]

On Thu, Sep 24, 2009 at 11:49:09AM -0300, Ying Zhang wrote:
> Hi list,
> 
> We have PIM-SM enabled on our network. Recently we've seen tons of log 
> messages on our switch:
> 
> CPU5 [09/24/09 14:21:47] IPMC ERROR ipmSysAddSession FAIL: Ar AddIpmcRec S 
> x.x.96.47 G 239.255.255.250
> CPU5 [09/24/09 14:21:47] IPMC WARNING ipmSysArAddIpmcRec rarAddIpmc FAIL G 
> 239.255.255.250 !
> CPU5 [09/24/09 14:21:47] IPMC WARNING k_chg_mfc FAIL New Session x.x.96.47 
> 239.255.255.250 is failed
> 
>  This has caused our switch to act slow and even drop some SNMP packets. I 
> did some search and found out it's SSDP for Windows Universal Plug and 
> Play.  On the mcast routing table, I can see many other users using the 
> same protocol, but only a few were logged with the error messages. I 
> suspect the user OS was affected by some virus. Just wondering if anyone 
> else has seen this and how to fix it on our end. 

Without having docs for those error messages it's hard to tell, but it looks 
as though the switch (which is also the PIM designated router?) is trying to 
create state for a new source. "SysAddSession" with an S and a G looks like a 
higher-level function, and Google says that k_chg_mfc is a function in pimd 
to add a forwarding cache entry.

Does the switch/router have some built-in or configured limit on how many 
sources/receivers/groups it can support? Or maybe just a memory limitation?

Bill.