From owner-freebsd-net Tue May 18 22:34:18 1999 Delivered-To: freebsd-net@freebsd.org Received: from obie.softweyr.com (unknown [204.68.178.33]) by hub.freebsd.org (Postfix) with ESMTP id C9D6315129 for ; Tue, 18 May 1999 22:34:13 -0700 (PDT) (envelope-from wes@softweyr.com) Received: from softweyr.com (homer.softweyr.com [204.68.178.39]) by obie.softweyr.com (8.8.8/8.8.8) with ESMTP id XAA13724; Tue, 18 May 1999 23:34:08 -0600 (MDT) (envelope-from wes@softweyr.com) Message-ID: <37424D4F.D9259DBA@softweyr.com> Date: Tue, 18 May 1999 23:34:07 -0600 From: Wes Peters Organization: Softweyr LLC X-Mailer: Mozilla 4.5 [en] (X11; U; FreeBSD 3.1-RELEASE i386) X-Accept-Language: en MIME-Version: 1.0 To: justin@apple.com Cc: freebsd-net@FreeBSD.ORG Subject: Re: Redirects and expire times References: <199905190411.VAA00649@walker3.apple.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org "Justin C. Walker" wrote: > > I don't have a lot of detailed experience with redirects, so I'm > kind of flying without a net (so to speak :-}): > > > From: Wes Peters > > Date: 1999-05-18 21:03:23 -0700 > > To: Jonathan Hanna > > Subject: Re: Redirects and expire times > > Jonathan Hanna wrote: > > > > > > What is the proper way of handling ICMP redirects? I expected > > > host routes to be added with an expire time, but apparently > > > they are permanent. > > > > > > I found one old reference to this, but no reply. > > > > > > > Date: Mon, 11 Mar 1996 15:09:15 -0600 (CST) > > > > From: Scott Mace > > > > To: hackers@freebsd.org > > > > Subject: Redirects and expire times... > > > > Message-ID: <199603112109.PAA15480@metal.ops.neosoft.com> > > > > > > > > I think it is a bug to add a host route after receiving a ICMP > redirect > > > > and NOT having any expire set on the route. If you have a > default routed > > > > host in a complex topology you can get into trouble when the > topology changes. > > > > I agree. At Xylan, we had numerous customer complaints about redirects > > filling the routing table and the only way to clear them (4.2 BSD based > > stack) was to reboot the switch. We added a 10-minute timeout on all > > redirect routes, figuring that redirects SHOULD be the exception rather > > than the rule. YMMV. We've had no customer complaints since > then. ;^) > Seems to me that redirects would be used for a variety of reasons: > (1) bad configuration; (2) multiple subnets on a single "wire" [so a > router *might* want to use redirects to avoid duplicating traffic on > the wire]; and mobility. > > If so, none of these seem to be especially "exceptions", but more > like "rules". Both (2) and (mobility) fall away as "rules" when you have VLANs and Group Mobility - the ability to move to different physical ports and have the VLAN follow you. ;^) (Pardon the advertising, it is a valid point. Switched LANs are very different creatures than the tradition hub/ethernet environment.) -- "Where am I, and what am I doing in this handbasket?" Wes Peters Softweyr LLC http://www.softweyr.com/~softweyr wes@softweyr.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message