Does any one know how to be sure trafic goes to the correct interface ? How does WINS react on a NT/Netapp host with multiple NIC's ? My NT servers are on the same subnet as the "e1a" interface and NFS clients on the "e0".

This is a subject area that is often asked about, and one for which you will find much good information available in the Microsoft Knowedgebase. You should find that:

http://support.microsoft.com/support/kb/articles/Q216/4/71.ASP

is a particular pertinent and helpful link on this particular subject, and:

http://support.microsoft.com/support/kb/articles/q181/7/74.asp

provides some good pointers to other related articles.

On the NetApp side, one thing that I would call your attention to is the "-wins" option on ifconfig. It specifically prevents a filer from registering a configured interface with WINS. What we found was that some of our customers had configured their networks in such a way that certain segments were topologically inaccessible to their Windows clients (either all of their Windows clients, or some subset thereof). By preventing the filer interfaces that are connected to those segments being registered with WINS, it makes it impossible for a Windows client to "accidently" select such an interface to communicate with using the algorithms described in the above "~Q216/71.ASP" article (which it might do if it has to resort to the "select an interface at random" part of the proceedings).

Keith