Both the Common Address Redundany Protocol (CARP) and the Virtual Router
Redundany Protocol (VRRP) map each virtual router instance to a mac address
belonging to the IANA's ethernet address block (00:00:5e). The
reserved block ranges from 00:00:5e:00:01:00 to
00:00:5e:00:01:ff (so you can not have more than 256 virtual routers
per ethernet segment). For example, any ip address of a virtual router
instance with an id of 23 is linked to the mac address
The routers itself communicate to each other by using the reserved multicast ip address 188.8.131.52, which is linked to the mac address 01:00:5e:00:00:12 (hint: hex(12) == dec(18)).
At least, CARP with FreeBSD 6.2 does not work in VMware Server 1.0.4 running on Linux 2.6.22. The carp devices go into their desired states (MASTER here, BACKUP there), clients on the local net even receive arp replies for the virtual ip addresses, but you can neither ping nor use any services on these addresses.
The vmnet kernel module (part of the freely available VMware Server) drops any ethernet paket if the destination mac address is not
You have to recompile the vmnet kernel module after editing one of its source files, driver.c. Locate vmnet.tar (usally in lib/modules/source/ in your VMware Server directory), unpack it, change in the newly created directory, open driver.c, locate a function called VNetPacketMatch, add the following lines logically or'ed to the return statement:
((destAddr == 0) && (destAddr == 0) && (destAddr == 0x5e) && (destAddr == 0) && (destAddr == 1))Save driver.c, recompile (make vmnet.ko) and put it into /lib/modules/`uname -r`/misc/. Restart VMware and have fun with CARP & VRRP!
Thanks to VMware for such a great product and giving it to the masses!