Date: Tue, 20 Mar 2007 13:05:25 -0700 From: Kevin Lahey <kml@patheticgeek.net> To: "Bruce M. Simpson" <bms@FreeBSD.org> Cc: freebsd-net@freebsd.org Subject: Re: PMTU Discovery support Message-ID: <20070320130525.01caad3d@yakko.patheticgeek.net> In-Reply-To: <45FF3D2F.3040000@FreeBSD.org> References: <994cd1cf0703050842r5e54daa6y5fe6af3083e15cd@mail.gmail.com> <45EC6E88.3080101@tomjudge.com> <20070305115615.W38684@orthanc.ca> <994cd1cf0703052105y375679a4t482f4e35988f9daf@mail.gmail.com> <20070319145422.39bfddcd@yakko.patheticgeek.net> <20070319172156.68cba0a9@yakko.patheticgeek.net> <45FF3D2F.3040000@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 20 Mar 2007 01:47:27 +0000 "Bruce M. Simpson" <bms@FreeBSD.org> wrote: > I believe PMTU measurements may only be relied upon for active TCP > connections, but it's been a while since I read this code. I think, according to RFC1191, that the probing should happen on any given connection after 10 minutes. Otherwise, a single ICMP message could permanently reduce the MTU of a connection for good. I believe that FreeBSD and others did it that way 10 years ago, when I did a survey of available PMTUD implementations. I wonder if all applicable TCP connections ought to be notified when the hostcache MTU is updated and when a hostcache entry with an MTU set is deleted? (For that matter, can an entry ever be deleted while outstanding connections are going to that host?) Kevin kml@patheticgeek.net
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070320130525.01caad3d>