From owner-freebsd-current@FreeBSD.ORG Sat Aug 2 04:12:22 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 50A1137B401 for ; Sat, 2 Aug 2003 04:12:22 -0700 (PDT) Received: from ns.tagnet.ru (ns.tagnet.ru [80.78.104.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1D89E43FB1 for ; Sat, 2 Aug 2003 04:12:21 -0700 (PDT) (envelope-from boris@tagnet.ru) Received: from dial-20.tagnet.ru ([80.78.104.20] helo=tagnet.ru) by ns.tagnet.ru with esmtp (Exim 4.20) id 19iuJ8-000J9C-RZ for freebsd-current@freebsd.org; Sat, 02 Aug 2003 17:12:19 +0600 Message-ID: <3F2B9C91.7010300@tagnet.ru> Date: Sat, 02 Aug 2003 17:12:17 +0600 From: Boris Kovalenko User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3) Gecko/20030312 X-Accept-Language: ru, en-us, en MIME-Version: 1.0 To: freebsd-current@freebsd.org References: <3F2A2B17.4020700@tagnet.ru> <3F2B787D.D1C4BCAC@mindspring.com> In-Reply-To: <3F2B787D.D1C4BCAC@mindspring.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: bge & vlan stranges X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 Aug 2003 11:12:22 -0000 Terry Lambert wrote: Hello! >Boris Kovalenko wrote: > > >> I have Compaq DL360G2 with Broadcom BCM5701 Gigabit Ethernet and >>FreeBSD 5.1R installed. There are no problems if I use bge as usual >>network card, but when I try to use 802.1Q vlans, I can't receive (only >>receive, sending is ok) packets more then 1456 bytes! What is the >>problem? BGE driver, VLAN driver or my network configuration? >> >> > >The encapsulation information is subtracted from your available >MTU, so that is correct. > >Some cards have a bogus feature that lets you send longer frames >than the normal MTU, but you can't rely on this feature being >interoperable between card vendors, or being supported on all >cards. > >I suppose you want to do this because you are trunking a channel >that goes to a border device, and for some reason you have disabled >receipt of all ICMP, instead of only abusable ICMP, and thus you >have broken end-to-end path MTU discovery. > >It would be best if you were to simply fix your ICMP. > > No, this is test machine, I have installed it two days ago and have firewall_type="OPEN" in my settings. So I have not disabled MTU path discovery You are speaking of. Nevertheless, what is "substracted from available MTU?" Why? The correct way it should work: 1500 bytes packet + 14 bytes ethernet header + 4 bytes CRC = 1518 bytes is standard ethernet frame and 1500 bytes packet + 14 bytes ethernet header + 4 bytes 802.1Q tag + 4 bytes CRC = 1522 bytes of standard 802.1Q encapsulated frame. All 802.1Q realizations I know working the same. >-- Terry > > > Boris