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Date: Thu, 14 May 2009 13:29:44 -0700 From: Stephen Hemminger <shemminger@...tta.com> To: Octavian Purdila <opurdila@...acom.com> Cc: netdev@...r.kernel.org, Bill Fink <billfink@...dspring.com>, Eric Dumazet <dada1@...mosbay.com>, Cosmin Ratiu <cratiu@...acom.com> Subject: Re: ports beeing reused too fast On Tue, 12 May 2009 18:52:25 +0300 Octavian Purdila <opurdila@...acom.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. -- -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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