IPMP with IPv6 test addresses

Quite a while back Dave Miner discussed how IP Multipathing can be done on the cheap in Solaris 10 by not using IPv4 test addresses at all and relying on the physical link state or alternatively using IPv6 link local addresses as test addresses. My first attempts at configuring the latter failed and not getting any response to my comment in his blog, I left it for more pressing work.

Recently I got back to this and managed to get it working.

Firstly you need to have /etc/inet/hosts and/or /etc/inet/ipnodes set up correctly with your IP address and hostname. In this example our host is called myhost with two interfaces bge0 and bge1.

/etc/inet/hosts:
192.168.1.1 myhost

Then configure your interfaces.

/etc/hostname.bge0:
myhost group production failover up

/etc/hostname.bge1:
up

/etc/hostname6.bge0:
group production -failover up

/etc/hostname6.bge1:
group production -failover up

You need to reboot for these configuration changes to take effect or you can pass the contents of the /etc/hostname* files as arguments to ifconfig.

Update: You need to ensure that both the host and the switch are set to autonegotiate for this to work.

Update 2007.09.20: According to this Sun document you do not need to mark an IPv6 test address as deprecated to prevent applications from using the test address. I've updated the configurations above to reflect this.