Low Speed (TCP Application) on Cat45k with SupV

[zehndermar]

Hello

I have a problem running a host server communication over a Cat45k:

If the server and host are connected over the Cat45k the application transports data at 15kB/s - if I connect the server and host over a Cat3750 - there are no problems!

I sniffed the traffic and see in both cases a lot (and I mean really a lot) of TCP DUP ACK's (Application running over TCP 6109).

First I tought the problem must be that the Cat45k don't support jumbo-frames - But in my sniff-trace I do not see any ethernet frames bigger than 1480B.

Does anybody have an idea?

Layout:

========

HOST---->WAN--->Router--->FW---->Switch--->Server

The issue occuers only if I use the 45k as the switch - it works fine with a Cat3750.

Thanks

Marcel

[owillins]

cat4500 with CatOS does not support jumbo frames its maximum size is 1522bytes , if your cat4500 switch contains IOS it will support jumbo frames upto 9216bytes.