Re: Cat 2924 Issue disappears with Cat2950

david.porter · ‎02-24-2003

Hello,

We have been experiencing an issue with one application (accounting). The application hangs regularly. The software vendor has told us that the log files show that it is network related. No other application/OS has had any connectivity issues so we were sceptical. However, as one of the last resorts, we replaced the switch that the servers are connected to. It was a Catalyst 2924 and we replaced it with a Catalyst 2950 and the problem disappeared.

The switches are configured identically, ie duplex settings, speeds etc. There are little or no errors on trunk ports. We are monitoring all switches with an SNMP management tool and notice some (but not many) discards on the Cat 2924 and only occassionally.

Any suggestions to the difference between a 2924 and 2950-24 that might explain this?

donewald · ‎02-25-2003

The 2950 is a more powerful/fast switch, but as you I am very skeptical of this being your fix. I think the fact, you mentioned, that this was the only application having problems would lead me to believe it was an application issue. Possibly good timing? Your accounting SW person found the problem when you plugged in the 2950? My guess... ;)

Hope this helps,

Don

david.porter · ‎02-25-2003

Thanks Don,

Since posting the message yesterday I stumbled across posts relating to issues with Ghost Multicast servers. There is an SOE pilot going on and I have now confirmed that there has been a Ghost Multicast server in use and the dates are a pretty good match to my problem. We will be testing this over the next couple of days and I will post the results.

Thanks again,

Dave

donewald · ‎02-25-2003

Dave,

One more note, since you mentioned Ghost (which uses multicast) for imagine/loading SW. If not properly handled this traffic could be getting flooded to all ports which would cause some severe problems, depending on how much the Ghost server is pushing. Check this link out for IGMP Snooping. Good stuff that might help you out.

http://www.cisco.com/en/US/partner/tech/tk648/tk363/technologies_tech_note09186a0080122a70.shtml

Regards,

Don

david.porter · ‎03-04-2003

Thanks Don,

Our testing has proved that it is the use of the Ghost Multicast server. I have had the SOE guys default to Unicast for the moment whilst I configure multicast properly. Thanks for the link, I will check it out.

Regards,

Dave