> > The gateway's IP address actually refers to two different machines. > > Naturally the gateway is used quite a bit, and the syslog fills up with "arp > > X moved from Y to Z on fxp0" messages. > > That's really not the right way to do it, and probably doesn't balance > the load as well as you might think it would. The right way to do it > is to advertise a single *multicast* MAC address, allocated out of the > local MAC space (i.e., first two bits 11), and have both routers join > the group; then both will get all the packets and can decide which > ones to forward. This gives you automatic fail-over trivially.
That is not valid according to the router requirements rfc (rfc1812), section 5.3.4: A router MUST NOT forward any packet which the router received as a Link Layer multicast unless the packet's destination address is an IP multicast address. A router SHOULD silently discard a packet that is received via a Link Layer broadcast but does not specify an IP multicast or IP broadcast destination address. When a router sends a packet as a Link Layer broadcast, the IP destination address MUST be a legal IP broadcast or IP multicast address. What Luckie does is clever but removing syslog messages seems like asking for trouble -- if two machines get the same IP address due to a mistake, tracking that down will be a bit more difficult. Redundancy should be handled by running the router discovery algorithm (e.g. routed) on each host and RIP or OSPF on the routers. Generally people use load balancing *between* routers and use a hefty enough router to handle all your local traffic on one net. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-net" in the body of the message
