It still uses a forwarding delay. Try "brctl setfd br0 1" to set it to 1 second. Alexander Indenbaum wrote: > Alex, > > That was my first thought too, but STP is disabled. > > On 10/11/06, Alex Zeffertt <ajz at cambridgebroadband.com> wrote: >> Alexander Indenbaum wrote: >> > Hello, >> > >> > I'm playing with dual-port NIC driver level link failover: >> > * Driver exposes single network interface to the OS and operates both >> > ports in active-passive failover mode. >> > * Upon Link down event on active port, driver switches active and >> > passive ports transparently for the OS. >> > >> > I'm testing the driver using Linux bridge module: "failover" dual-port >> > NIC connected with two cables back-to-back to eth0 and eth1 which are >> > part of br0 bridge. >> > >> > I simulate link fail with following scenario: >> > * At t0 both eth0 and eth1 port links are UP, traffic is accepted by >> > eth0 and forwarded to br0 >> > * At t1 I manually unplug eth0 cable, causing link to go down. >> > "Failover" driver switches the traffic immediately from eth0 to eth1, >> > while using the same MAC address. >> > * From t1 till t1+12 secs packets are accepted by eth1 but dropped by >> > bridge and not forwarded to br0. >> > * At t1+12 secs bridge starts forwarding packets from eth1 to br0 >> > >> > Hmm... I would expect that eth0 link down event would flush from >> > bridge's table any MAC address associated with the port and that the >> > bridge would start forwarding packets from eth1 to br0 immediately. >> > >> > Why does it take ~12 secs for bridge to learn that MAC address moved >> > from eth0 to eth1 in the described scenario? >> > >> >> It may be spanning tree, rather than MAC address learning that takes >> so long. Bridges spend a while just listening before forwarding, to >> avoid becoming part of a bridging loop. >> >> Experiment with: >> >> brctl showstp br0 >> brctl stp br0 off >> brctl setfd br0 1 >> >> Alex >> >> > >
