Hey everyone, Last week's converstaion on 6500 scalaibility numbers prompted me to dig back into the performance issues I have on a pair of boxes. I discovered two issues, both related to the presence of CSMs in the chassis. An important note about my scenario - I have two basically identical installations, one which performs brilliantly, one which doesn't.
The first is a semi-documented bridged mode issue. The CSM is not enough of a bridge to bridge traffic that stays on the server VLAN. It must be bridged onto the client VLAN, handled by the MSFC, and then bridged back. (I don't have the cisco.com reference for this, but could find it.) It seems that if the two endpoints are directly-connected to the client SVI, that traffic is software switched. This only affects servers without a direct layer 2 path on a downstream access switch. The second issue is a complete mystery to me. Many flows directed at VIPs (every flow?) on the CSM have their first packet switched in software. This adds up to an enormous amount of traffic for us. We also have a well-performing pair of 6500s that do *not* display this behavior. I always thought that service module internal interfaces behaved just like normal interfaces, except that they traversed the bus and not the fabric. Clearly, this isn't the case - there's something else going on. Anyone know anything about process switching the first packet of flows to service modules? -- Ross Vandegrift r...@kallisti.us "If the fight gets hot, the songs get hotter. If the going gets tough, the songs get tougher." --Woody Guthrie _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/