how to capture only first few packets of every tcp session?

Question

In my stress test using jmeter, I am trying to find out the root cause of connection reset, hostconnect exception and such errors on jmeter client. The only way I can think of is to capture the packets and see if I am getting tcp reqeusts and what response the server is sending.

However I am failing to write bpf filter, so that I just capture tcp 3 way handshake and first get request. I don't want to capture rest of the stuff, because I steram huge mp4 files in my test, which will simply bring down my capture machine, it incidentally is also my server under test.

Any ideas?

Answer 1

Wireshark forum has the exact question answered.

http://ask.wireshark.org/questions/15057/how-to-capture-tcp-3-way-handshake

Really interesting solution.

Answer 2

For TCP low level analysis, I would go with Wireshark.
http://www.wireshark.org/
It is free, and very good tool for protocol analysis at any level.
Just use each tool for its intended purpose: Jmeter is a load generator.