On Thu, Dec 13, 2001 at 10:22:50PM +1100, Mathew McKernan wrote:
> Hey all, Hi there, > We currently are having some network problems across our microwave link. We > have 2 seperate buildings linked by this microwave link. Both LANs are 100MBps > and the link is 10MBps. In an attempt to stop excess data from flowing across > the link we placed a bridge between the LAN and radio at both buildings. > Unfortunetly both of these bridges are only 10MBps. So data is flying at > 100MBps to the switch that each bridge is on and comes to a grinding halt and > trickles through the bridge to the radio onto the other building. Because there > is a high amount of traffic about twice a day the bridge "locks-up". i.e. > doesnt forward packets and its CPU locks up. We have swapped the bridges and no > success. On closer inspection we found that its buffer was overflowing What bridge were you using for this? What underlying hardware, operating system, network cards? How did you diagnose that 'its buffer was overflowing'? > So I was reading on the internet and found the Linux Ethernet Bridge project. I > have build a box to replace the bridge that keeps on "locking up". The box has > 2 LAN cards that are both 100MBps. We are hoping that this box will not crash > and not drop packets because its buffer overflows. Can anyone confirm that the > Linux box will hold the data and eventually get it across the link? Heh, well I can assure you that there is no code in the linux ethernet bridge code to actively lock up the machine under load ;) Under no circumstance should active network equipment 'lock up' due to high load. I'm not exactly sure what you mean with your question. If you are asking whether linux ever drops packets, I can assure you that it will. If you are bridging from 100Mbit to 10Mbit, it takes ten times longer to transmit the data than to receive it, so if insist that no packets be dropped, even if you put the 100Mbit under load for a day, you will need 10 days worth of 10Mbit buffering capacity in the bridge, which is about a terabyte. It's generally acceptable to drop traffic under load. The end hosts are supposed to detect this and retransmit. It will not benefit performance if this happens, but things should keep working. cheers, Lennert _______________________________________________ Bridge mailing list [EMAIL PROTECTED] http://www.math.leidenuniv.nl/mailman/listinfo/bridge
