From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4D519E97.40706@ll.mit.edu> Date: Tue, 8 Feb 2011 14:50:47 -0500 From: Jeff Mitchell MIME-Version: 1.0 References: <4D519986.7070000@ll.mit.edu> <4D519DC8.9070908@candelatech.com> In-Reply-To: <4D519DC8.9070908@candelatech.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Bridge] Bridge suddenly only passes traffic if in promiscuous mode List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ben Greear Cc: "bridge@lists.linux-foundation.org" On 02/08/2011 02:47 PM, Ben Greear wrote: > On 02/08/2011 11:29 AM, Jeff Mitchell wrote: >> Hello, >> >> I have a bridge to various interfaces. There is an IP address on the >> bridge, and hosts on the interfaces connected to the bridge use the >> bridge's IP address as a gateway. STP is off and the forwarding delay is >> set to 0. >> >> This has been working fine, however, today I needed to change around >> some IPv6 addresses on the connected hosts. I made the IPv6 changes and >> rebooted those boxes, only to find that suddenly no traffic -- IPv4 *or* >> IPv6 -- was passing through the bridge. >> >> When I pulled up tshark to see what was going on, traffic suddenly >> started flowing again. And even as I type this, as long as tshark is >> running on that interface (no matter what the capture filter is), >> traffic is flowing. The moment I stop tshark from running, traffic >> stops. IOW, the bridge is only passing traffic while in promiscuous mode. >> >> I didn't change the IP address on the bridge itself. As far as I can >> tell I didn't do anything odd whatsoever. But I have no idea what's >> causing this and I'd really like to not reboot the box if at all possible. >> >> Does anyone have any idea what might be causing this and/or how to >> troubleshoot this? > > What kernel version? > > And, you are sniffing the physical interface, or the bridge? > > Maybe send us output of brctl show, and ifconfig -a? > > Promisc bit is sometimes hard to detect properly, so if you can, please > post /sys/class/net/[iface-name]/flags > If bit 0x100 is set, the NIC is actually promisc, regardless of what > ifconfig -a shows. I found other funky behavior (sendmsg denied when trying to ping via IPv6) and users had trouble accessing services on the box, so I already initiated a reboot of the box -- I need those services up. :-| If it happens again I'll be sure to get you that info. However, here's what I *can* provide: 2.6.36 kernel, and sniffing the bridge. (There's actually no physical interface on the bridge -- this is on purpose, to prevent any problems on the bridge from affecting the one physical interface on the box, and thus my ability to get in and fix things.) --Jeff