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From: Martijn van Oosterhout <kleptog@svana.org>
To: Andrea G Forte <andreaf@cs.columbia.edu>
Cc: netdev@oss.sgi.com, linux-net@vger.kernel.org
Subject: Re: Very slow change of IP in kernel (slow socket?).
Date: Wed, 22 Dec 2004 17:26:32 +0100	[thread overview]
Message-ID: <20041222162632.GC29278@svana.org> (raw)
In-Reply-To: <41C895D6.2040001@cs.columbia.edu>

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Seems long, but have you condered other possible delays, like ARP,
routing daemons, etc. BTW, I don't quite understand what you mean by
changing IPs, because "ip route add" adds routes, not IPs. Presumably
you're using an unbound UDP socket. You need to be a bit clearer about
what you're actually trying to do...

On Tue, Dec 21, 2004 at 04:29:58PM -0500, Andrea G Forte wrote:
> Hi all,
> 
> after some talking I decided to try again and post a specific thread for 
> this problem.
> I noticed that when I change IP address for the same wireless card 
> (since I am moving to a different subnet I need a new IP), the actual 
> change in the kernel happens between 300 to 500 ms later. In particular, 
> after changing the IP (ip route add...) and updating route table and 
> default gw, the actual data packets are sent using the new IP only after 
> 300 to 500 ms after setting all the above.
> Does anyone of you know what this could be related to? Or, does anyone 
> of you know where in the kernel code I could start looking for some answers?
> I have already had some feedback with suggestions to look into the 
> route_cache, however this does not seem to me as a route problem but 
> more as a socket problem and perhaps some kind of timer that is set to 
> refresh the socket info in the kernel.
> 
> Any help would be really appreciated.
> 
> Thanks all,
> Andrea
> -
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-- 
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.

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  parent reply	other threads:[~2004-12-22 16:26 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-12-21 21:29 Very slow change of IP in kernel (slow socket?) Andrea G Forte
2004-12-22  8:27 ` bert hubert
2004-12-22 16:26 ` Martijn van Oosterhout [this message]
2004-12-22 17:37   ` Andrea G Forte

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