NFS 4
 

NSF 4 has a callback feature where the server will try to contact the client.
Due to firewalls our server cannot ever contact the client. It is causing error messages and affecting our auto mount set up.

Does anyone know how to turn off the callback feature? We are running Red Hat Enterprise 5.3 on the server and RH 4.6 on the client.

You're probably best off asking RH that one.