Messages in this thread | | | Date | Wed, 19 Dec 2007 11:53:06 -0500 | From | "James Nichols" <> | Subject | Re: After many hours all outbound connections get stuck in SYN_SENT |
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> So you see outgoing SYN packets, but no SYN replies coming from the remote > peer ? (you mention ACKS, but the first packet received from the remote > peer should be a SYN+ACK),
Right, I meant to say SYN+ACK. I don't see them coming back.
> When the problem comes, instead of restarting the application, please take a > tcpdump of say 10.000 packets. > Then turn off tcp_sack and take a 2nd tcpdump sample, and make both samples > available to us.
I can take these captures and take a look at the results. Unfortunately, I don't think I'll be able to make the captures available to the general public.
> If turning off tcp_sack makes the problem go away, why dont you turn it off > all the time ?
Unfortunately, I think that will be the answer if I can't get any help fixing this problem in the kernel. It's a bummer, because many of the remote hosts my application communicates with are on wireless links, so there may be performance implications to turning SACK off.
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