Date: Mon, 8 Mar 2004 23:26:34 +0200 From: Ruslan Ermilov <ru@freebsd.org> To: Andre Oppermann <andre@freebsd.org> Cc: net@freebsd.org Subject: Re: Cached IP routes Message-ID: <20040308212634.GA30394@ip.net.ua> In-Reply-To: <404C5F65.446E20A8@freebsd.org> References: <20040308102038.GA28502@ip.net.ua> <404C5F65.446E20A8@freebsd.org>
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--SLDf9lqlvOQaIe6s Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 08, 2004 at 12:56:21PM +0100, Andre Oppermann wrote: [...] > > We still have a similar problem in in_gif_output(), and I wonder what > > would be a correct fix, given the above? >=20 > in_gif_output() is not the same as the route cache of ip_forward. It > just caches the route to the tunnel destination which normally stays > the same over long periods of time. The only problem you might run > into are route changes. At one point in time your best path is the > default route so a pointer to it is being cached in sc->gif_ro. Later > you have a better via some other gateway. This won't be picked up by > the gif route cache. In 5.2 and -CURRENT you can scrap the route > cache and just give a NULL to ip_output instead of a route. This way > you will always use the best path to destination. >=20 Yes, that's exactly the situation I'm faced with (yes, I know how the routing code works). For others. Initially, the route to the gif(4) tunnel's destination is through the default route. I then add an explicit host route to the tunnel destination, and "route change default" to point to the tunnel (gif0). The result is that in_gif_output() caches the default route as the route to "tunnel destination", and doesn't pick up the "best match" host route. Of course, I'm working around this by deleting and re-adding the default route, but I wonder what in your opinion would be the correct fix. As you properly mentioned, in_gif_output() is significantly different from ip_forward() because the rt_dst is always the same. Cheers, --=20 Ruslan Ermilov FreeBSD committer ru@FreeBSD.org --SLDf9lqlvOQaIe6s Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFATOUKUkv4P6juNwoRAjKpAJ9gZm8l/aJi24oAKbM4fp5/9t0YzQCdHbYx 2U4h1bKjXP/azNW2UNG/zuk= =xGAN -----END PGP SIGNATURE----- --SLDf9lqlvOQaIe6s--
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