best practice to watch TCP parms of established sockets

[Chuck Swiger]

Hi--

On Feb 17, 2010, at 8:03 AM, Harald Schmalzbauer wrote:
> while doing some ZFS tests with RELENG_8 I recognized a mysterious performace drop after an hour uptime.
> Now my first idea is to compare MSS and windows sizes before and after the performance drop.
> How do I best capture them? tdpcump? It's GbE linkspeed...

It seems more likely that ZFS is running into slowdowns from resource contention, memory fragmentation, etc than your network would suddenly drop out, but tcpdump -w outfile.pcap is a good method of looking....

Regards,
-- 
-Chuck