Date: Tue, 13 Nov 2007 10:45:14 -0600 From: Erik Osterholm <freebsd-lists-erik@erikosterholm.org> To: freebsd-questions@freebsd.org Cc: girishvenkatachalam@gmail.com Subject: Re: PF, bridge, states and window scaling problem Message-ID: <20071113164514.GA86464@aleph.cepheid.org> In-Reply-To: <20071113135523.GA13178@saraswathy.susmita.org> References: <669132de0711121208n32bfb827p4984c6d3383da713@mail.gmail.com> <20071113022053.GA17768@saraswathy.susmita.org> <20071113054220.GA74564@aleph.cepheid.org> <20071113132734.GA16728@saraswathy.susmita.org> <20071113135523.GA13178@saraswathy.susmita.org>
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On Tue, Nov 13, 2007 at 07:25:23PM +0530, Girish Venkatachalam wrote: > On 18:57:34 Nov 13, Girish Venkatachalam wrote: > > I just read the post you linked. Thanks. :) > > I read the post once again and it looks as though I understood what is > mentioned there. > > The 'no-df' in scrub rule clears the Don't fragment bit in the IP > header. When a host wrongly sends fragmented packets with the DF bit > set, this scrub rule "correctly" resets the DF bit. > > Now since the host made the mistake of sending a fragmented packet with > DF bit set ( this is like saying " Please don't fragment my packet, but > I myself have fragmented". Odd...) no-df scrub rule causes trouble. > > Scrub never causes trouble with properly formed packets. > > regards, > Girish Ah, that makes sense! In fact, if I'd done a little more reading, I'd see that OpenBSD suggests the same: http://www.openbsd.org/faq/pf/scrub.html They mention that there are some problems (NFS specifically, and "some online games"). I believe that we've also seen some weird behavior with Active Directory, but I'd have to check to make sure. Thanks for the information! Erikhome | help
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