From owner-freebsd-stable Wed Jul 5 23:39:48 2000 Delivered-To: freebsd-stable@freebsd.org Received: from info.iet.unipi.it (info.iet.unipi.it [131.114.9.184]) by hub.freebsd.org (Postfix) with ESMTP id 0ED0A37C15D for ; Wed, 5 Jul 2000 23:39:44 -0700 (PDT) (envelope-from luigi@info.iet.unipi.it) Received: (from luigi@localhost) by info.iet.unipi.it (8.9.3/8.9.3) id IAA82096; Thu, 6 Jul 2000 08:40:15 +0200 (CEST) (envelope-from luigi) From: Luigi Rizzo Message-Id: <200007060640.IAA82096@info.iet.unipi.it> Subject: Re: Ethernet MTUs > 1500? In-Reply-To: <396368C9.C3C5A50F@polytechnic.edu.na> from Tim Priebe at "Jul 5, 2000 05:56:41 pm" To: tim@iafrica.com.na Date: Thu, 6 Jul 2000 08:40:15 +0200 (CEST) Cc: David Gilbert , Kevin Oberman , "Louis A. Mamakos" , Joerg Micheel , freebsd-stable@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL61 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > just curious, what do we do when we have multiple encapsulation ? > > (i.e. is this allowed ?) ... > I am not sure what you mean. If you mean "VLAN encapsulation", then it > is a misunderstanding. The standard Ethernet frame is not encapsulated. ok think of the following: I have a st machine which goes through a VLAN bridge out to a trunk interface, which in turn goes into a VLAN bridge which does trunkinking again ... basically you might end up with frames being encapsulated multiple times (and decapsulated on the reverse path). Now i wonder if this is allowed by the vlan spec and also how does a vlan bridge behaves when it sees a vlan-tagged frame on a non-trunk port. I do know how my FreeBSD-based vlan bridge behaves -- it does multiple encaps, but then if a packet becomes too large it is silently dropped by the interface. cheers luigi -----------------------------------+------------------------------------- Luigi RIZZO, luigi@iet.unipi.it . Dip. di Ing. dell'Informazione http://www.iet.unipi.it/~luigi/ . Universita` di Pisa TEL/FAX: +39-050-568.533/522 . via Diotisalvi 2, 56126 PISA (Italy) Mobile +39-347-0373137 -----------------------------------+------------------------------------- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message