Messages in this thread | | | Date | Sun, 14 Feb 1999 08:30:25 -0500 | From | Neil Cherry <> | Subject | Re: [patch] ts_recent in tsecr of syn-ack [Re: Weird tcp performance differences with 2.0 and 2.2 kernels] |
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Andrea Arcangeli wrote:
<SNIP>
> This is something of crazy and should be a bug in porcupine or in the > middle man. > > >and porcupine is waiting for my ack. Does it look like receiver troubles > >to you?.. or is this just coincidence and tcpdump is being a PITA? It > > Don't know. Trusting the SOCK_PACKET code looks like it's a sender bug to > me. > > >Anyone see exactly this problem on a _non_ isdn connection? > > Really yesterday I tried an ls in /pub/security and it was very slow (as > _everything_ else from here) but worked after a while. > > Would it be possible that porky (or some other men in the middle) when > receive the syn-ack it just does (jiffies - tsecr) and use the computed > value to set a bogus RTO and/or to do some other mess? I don't think it's > the case but to give a try I changed the 2.2.2-pre2 linux TCP stack to do > exactly what porcupine does (reverse engeneered from the tcpdump, I don't > have the time to see which OS is running porcupine) in the synack > timestamp case. > > You may want to give a try to this my patch and see if the bad behavior > will go away.
Andrea, thank you, the patch fixed the problems I was having. I have a cable modem connection to the internet. Without the patch ftp would stall (to any server), pings response would go to 12 Seconds (12000 mS), and I would have some problems using sitecopy to a local server (on my internal LAN).
With the patch, ftp's no longer stall and ping response is back to 83 ms for router (next hop) and ~300 ms for servers outside my ISP.
-- Linux Home Automation Neil Cherry ncherry@home.net http://members.home.net/ncherry (Text only) http://meltingpot.fortunecity.com/lightsey/52 (Graphics)
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