From: Brian Tao taob@nbc.netcom.ca
According to the man page:
The interface name vh is used to specify IP virtual host addresses associated with the filer. Only alias addresses (using the alias option) may be assigned to the vh interface.So I can assign multiple IP's to vh... how do I bind those IP's to a physical interface? Or is this only used for the virtual hosting feature in the HTTP server?
Unfortunately the doc on this subject doesn't really spell all this out in a manner that could be described as crystal clear, but...
My understanding is that the vh interface is just associated with the HTTP daemon's virtual hosting feature. The addresses on vh are the ones that the web server runs through /etc/httpd.hostprefixes to locate a target specific home directory for inbound HTTP requests. However, there is of course the "little" issue of packets destined for a vh address being able to find their way into a filer in the first place, which will inevitably require some cooperation from the real, physical interfaces. This could conceivably be made to happen via routing trickery, perhaps using host routes to ensure that packets destined for vh addresses get fired at a filers physical interfaces on their last hop, or maybe even full network routes, where the vh addresses are on a subnet that is entirely internal to the filer and the physical interfaces form routes to that subnet.
Failing this, then you're right, there needs to be some correlation between vh addresses and the addresses being supported by the physical interfaces. Alas I haven't been able to find a description of whether this is a manual or automatic process. I have to assume manual for now. My own experience starts and ends with loading up just the physical interfaces with addresses, and leaving the vh interface alone.
Keith