It can be tough making NFS play nice amongst different distros and firewalls. I'm sharing my Eclipse workspace on my Ubuntu (Debian) desktop with my CentOS (Redhat Enterprise) server. (That's not a mistake, my server is actually my NFS client in this scenario. You could easily swap these roles if you wish)Assuming you allow all outbound traffic on your client (I recommend this excellent iptables config file rc.firewall_023.txt), you should now be able to mount the NFS share on the Redhat box.
DEBIAN:I used port numbers and config instructions at http://wiki.debian.org/?SecuringNFSFollow those instructions exactly and you'll have a NFS server configuration that uses static ports (instead of random assignements)REDHAT:1. Create the file "/etc/sysconfig/nfs" and add the following contents:STATD_PORT=32765STATD_OUTGOING_PORT=32766LOCKD_TCPPORT=32768LOCKD_UDPPORT=32768MOUNTD_PORT=327672. (Probably not necessary for most, but here for completeness) Append the following to the file "/etc/services":rquotad 32769/tcp # rpc.rquotad tcp portrquotad 32769/udp # rpc.rquotad udp port3. Restart the nfslock service:/etc/init.d/nfslock restart4. Run /usr/sbin/rpcinfo -p and make sure all the ports above have changed and match their ubuntu numbers. (/usr/bin/rpcinfo on ubuntu)5. I run firestarter on Ubuntu which is exporting my NFS share. I added the following policy rules for inbound traffic:Allow 32767 (from my client machine's IP)Allow 2049 (from my client machine's IP)Allow 111 (from my client machine's IP)