From:   "Albert D. Cahalan" <acahalan@cs.uml.edu>
Message-Id: <200101290245.f0T2j2Y438757@saturn.cs.uml.edu>
Subject: Re: [PATCH] dynamic IP support for 2.4.0 (SIOCKILLADDR)
To:     vii@altern.org (John Fremlin)
Date:   Sun, 28 Jan 2001 21:45:02 -0500 (EST)
Cc:     linux-kernel@vger.kernel.org, netdev@oss.sgi.com,
        paulus@linuxcare.com, linux-ppp@vger.kernel.org,
        linux-net@vger.kernel.org
In-Reply-To: <m2d7d838sj.fsf@boreas.yi.org.> from "John Fremlin" at Jan 27, 2001 10:54:51 PM
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John Fremlin writes:

> When the IP address of an interface changes, TCP connections with the
> old source address are useless. Applications are not notified of this
> and time out ordinarily, just as if nothing had happened. This is
> behaviour isn't very helpful when you have a dynamic IP and know
> you're probably not going to get the old one back. In that case, you
...
> I patched userspace ppp-2.4.0 to use this functionality. It would be
> better if SIOCKILLADDR were not used until we are sure that the new IP
> is in fact different from the old one, but pppd in demand mode would

I get the same IP about 2/3 of the time, so it is pretty important
to avoid killing connections until after the new IP is known.