I'm currently installing a number of Apple Xserve boxes running Mac OS X Server (10.6). After poking and prodding for a while I can't find any obvious way, or documentation telling me how, to set up the 2 ethernet ports in a failover or load-balancing configuration.
There seems to be an obvious way to do link aggregation, but not failover or load-balancing? What's the default configuration if I enable both ports with the same (manually configured) IP address?
It's not clear exactly what you mean by "load balancing" in this context.
If you want to use both ethernet ports to connect to the same switch in order to gain higher throughput (2Gbps) and also to gracefully degrade to 1Gbps if either cable becomes unplugged, then you should set up 802.3ad link aggregation.
802.3ad is a layer-2 network concept, which means it happens before you give an IP address to a network interface. When you create the link aggregation, you'll get a new "virtual" interface which you can assign an IP address to.
You need have a switch that supports this, and you need to configure the switch ports as such.
See also the description on Apple's Mac OS X Server Networking page.
