Nfs – connection refused with nfs server

nfs

I have an issue with NFS.
I have two rhel4 servers. sys1 and sys2.
I have a directory exported from sys1 and sys2 is the nfs client trying to access the mount.
I'm able to mount, but after a certain amount of time I get
"RPC: Remote system error: Connection refused."
and then I restart nfs services, quotas, deamon, mountd and lockd.
Then it works fine again.

Any way to fix this.
Thanks.

Best Answer

Is there any firewall with timeouts between sys1 and sys2?