From owner-freebsd-net Wed Oct 23 11:41:27 2002 Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 041F537B401 for ; Wed, 23 Oct 2002 11:41:26 -0700 (PDT) Received: from vineyard.net (K1.VINEYARD.NET [204.17.195.90]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4BA9443E42 for ; Wed, 23 Oct 2002 11:41:25 -0700 (PDT) (envelope-from ericx@vineyard.net) Received: by vineyard.net (Postfix, from userid 0) id 3980891F68; Wed, 23 Oct 2002 14:41:19 -0400 (EDT) To: freebsd-net@freebsd.org Subject: VLAN problems with replies to broadcast From: Charlie Root Reply-To: Charlie Root Date: Wed, 23 Oct 2002 14:41:19 -0400 Message-Id: <20021023184119.3980891F68@vineyard.net> Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org We have built a machine with 3 vlan parenting off an fxp. The vlan are bridged and vlan0 has an IP. The fxp has no IP and is excluded from the bridge group. ** root@fw ** ~ ** Sat Oct 19 18:38:08 # ifconfig fxp0: flags=8943 mtu 1500 ether 00:02:b3:5b:dd:98 media: Ethernet autoselect (100baseTX ) status: active vlan0: flags=8843 mtu 1500 inet 192.168.10.1 netmask 0xffffff00 broadcast 192.168.10.255 ether 00:02:b3:5b:dd:98 vlan: 5 parent interface: fxp0 lo0: flags=8049 mtu 16384 inet 127.0.0.1 netmask 0xff000000 vlan1: flags=8843 mtu 1500 ether 00:02:b3:5b:dd:98 vlan: 10 parent interface: fxp0 vlan2: flags=8843 mtu 1500 ether 00:02:b3:5b:dd:98 vlan: 20 parent interface: fxp0 The fxp is plugged into an SMC Tigerswitch. The SMC is configured to pass VLAN's 5, 10 and 20. Everything works except replies to broadcast packets. e.g. using tcpdump I observe an arp request coming from the SMC switch. tcpdump reports that there are 3 packets (one tagged with each VLAN -- not clear whether there really are 3 distinct packets or whether tcpdump is make a best-effort to report a broadcast packet). tcpdump also displays a single reply tagged with the one correct VLAN (the remote host's traffic is tagged by the SMC). The remote host does not receive the reply. Presumably the SMC is not forwarding the packet. The same behaviour is observable for dhcp requests. Is there some reason why a packet sent in reply from a VLAN interface might be tagged differently such that the SMC would refuse it? Has anyone else observed such behaviour? Can anyone suggest some tests I might try or further reading? Thank you for your time. --ericx To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message