From: Stephen Hemminger <shemminger@vyatta.com>
To: Octavian Purdila <opurdila@ixiacom.com>
Cc: netdev@vger.kernel.org, Bill Fink <billfink@mindspring.com>,
Eric Dumazet <dada1@cosmosbay.com>,
Cosmin Ratiu <cratiu@ixiacom.com>
Subject: Re: ports beeing reused too fast
Date: Thu, 14 May 2009 13:29:44 -0700 [thread overview]
Message-ID: <20090514132944.561a1691@nehalam> (raw)
In-Reply-To: <200905121852.26099.opurdila@ixiacom.com>
On Tue, 12 May 2009 18:52:25 +0300
Octavian Purdila <opurdila@ixiacom.com> wrote:
>
> > I raised the issue to the original author of the proposed RFC and added
> > the issue to the ongoing review of the draft.
> >
> > There is a suggested workaround using a bitmap but it seems like it would
> > be expensive to implement:
> >
> > http://ietfreport.isoc.org/all-ids/draft-ananth-tsvwg-timewait-00.txt
>
> OK, I now understand how TW could be an issue here - I didn't realize that we
> could have sockets in TW on the server side.
>
> Since the workaround seems expensive, would it be acceptable to add a new
> sysctl option to disable port randomization?
>
> Thanks,
> tavi
>
Patches welcome. Also, it matters whether application does bind() first
or port is assigned as part of the accept. In the later case the starting
point is a hash of the 5 tuple and changes only every 5 minutes. Linux
also reuses ports in time wait, so it will reuse sockets more aggressively
than other hosts; this existed before port randomization.
--
prev parent reply other threads:[~2009-05-14 20:29 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-08 20:11 ports beeing reused too fast Octavian Purdila
2009-05-09 6:58 ` Eric Dumazet
2009-05-09 13:11 ` Octavian Purdila
2009-05-09 15:17 ` Eric Dumazet
2009-05-09 16:16 ` Eric Dumazet
2009-05-09 19:31 ` Bill Fink
2009-05-09 19:41 ` Octavian Purdila
2009-05-09 22:45 ` Stephen Hemminger
2009-05-12 12:32 ` Octavian Purdila
2009-05-12 15:11 ` Stephen Hemminger
2009-05-12 15:52 ` Octavian Purdila
2009-05-14 20:29 ` Stephen Hemminger [this message]
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