NFSv4 Kerberos tickets expiring

[Sashikanth Madduri]

Hello everyone,
                            I am setting up a new lab and I have to
make NFS secure to provide good
authentication and prevent someone from
sniffing the traffic.  All the machines
are running RHEL 4.

I am considering NFSv4 . Since NFSv4 uses kerberos, what will happen
if the client tickets expire? Do the client machines have to renew
their tickets and mount the directory again? What if there is some
dirty data when the tickets expire?

In addition to the above, will there be any other problems with NFSv4.

Thanks.

Sashi.
UCSD.