Confused about NFS

[Arthur Pemberton]

I am a bit confused about NFS in fedora/centos:

system-config-securitylevel has a checkbox option for NFS4 which does
little in the way of opening up firewall access to NFS. checking the
nfs-utils package, I see no mention of NFS4, so I'm left to assume
it's not NFS4 on the system.

/etc/sysconfig/nfs is very useful for configuring NFS for access
through the firewall, but there is no sample version of the file.

What's the purpose of the NFS4 checkbox in securitylevel, and why is
NFS access so complicated to setup?

-- 
Fedora Core 6 and proud