JOHN@heap.cisco.com (John Wright) (05/08/91)
All 8.2 Bridging releases, including IGS. Fix to be in 8.2(4). If a cisco running bridging receives a packet from a host using a SOURCE MAC address of FFFF.FFFF.FFFF (i.e. the BROADCAST address) we then 'learn' that the broadcast address is a local address on that interface. Any future broadcasts received on that interface will not be flooded as we think that is local traffic. Show bridge will display something like: BG Hash Address Action Interface Age RX count TX count 1 00/24 ffff.ffff.ffff receive Ethernet0 S 382800 0 Where a normal display would be: BG Hash Address Action Interface Age RX count TX count 1 00/9 ffff.ffff.ffff receive - S 107 0 NOTICE: under the interface column an interface being displayed. This is an indication of the problem. Normally there should be a "-" in this column for the broadcast address. A workaround for this problem is to remove the broadcast address from the bridge table using: NO BRIDGE 1 ADDRESS FFFF.FFFF.FFFF If this is applied to a system which does not currently have the problem it will prevent it from happening. This command would need to be given upon every system reload. If you are network loading a configuration file the command will be processed at that time. ------- DEC MOP boot service packets do not get bridged when DECnet routing is enabled. A problem was introduced in 8.2, fix to be in 8.2(4) release, in handling MOP which broke the bridging of MOP boot requests. The IGS does not have this problem. ===== John Wright Customer Engineering cisco Systems, Inc. -------