Hi, I searched the mailman archives for this topic and there were some older messages that indicate that a large MTU should work, but it's not going too well here. I've got three systems (A, B, and C) with kernel 2.6.12.2; there are back-to-back gigabit connections between A & B and between B & C. Testing prior to bridging, the MTU is set to 9000 on every interface and a 100 MB iperf transfer is made between A & B and then between B & C with no problems. When the two interfaces on B are bridged and an A to C transfer attempted, a few packets (four, in the test I'm looking at now) go through and the session freezes. One of the bridged interfaces on B shows some frame errors. With an MTU of 1500, and everything else left the same, the bridge works perfectly. What additional information can I provide? Thanks, Tad