FC6 / nfs(v3) issue

[Bob Kryger]

FC6 / nfs issue: I have a Solaris 8 NFS server that has 2 interfaces to 
the LAN. Each interface has its own ip address and hostname. One 
interface is virtual (aka sub-interface) for veritas HA support. All nfs 
(automounts) go through the virtual interface. On my new FC6 systems I 
cannot mount the exported mountpoints via the virtual interface, but can 
via the standard interface. I have, of course, tested the virtual 
interface from the FC6 box, with ping and ssh. I see the nfs traffic on 
the server via the virtual interface (snoop), and on the FC6 client 
(tcpdump), but the connection does not complete.

Ideas?
Suggestion of how to proceed in debugging?

BTW - I have some 30 FC5 systems which handle this NFS mount w/o 
problem. I wonder what might have changed, I have not been able to find 
what that may be.

Thanks
Bob