Hi,
I installed Fedora Core 2 on a computer that I want to export a file system to a working NFS group.
I found that I cannot make it mountable. With the same settings it was fine in RH 8 and 9.

When runnig "rpcinfo -p" from another machine in the system i get:
"rpcinfo: can't contact portmapper: RPC: Remote system error - No route to host"
reading 'NFS-HOWTO' got me as far as "you are a victim of overzealous firewall'. The HOWTOs I was referred to are not informative enough for me.

As far as I can tell I have no iptables installed.
I think an unhealthy sign is that /proc/fs/nfs/exports is empty save for comments.

Anybody knows how to fix this ? What else should I check ?
How to controllably (preferably) diable the firewall so that what is said in /etc/exports is actually exported ?

Well, it turns out that controlling the firewall behaviour with respect to NFS is not easy,
as perhaps lack of replies suggests. It is to do with, normally, port numbers beeing given
to some processes on first come - first serve basis. You would need to first fix the processes
to ports, before the firewall can be set to let them through. NOT easy, for me anyway.
There are some instructions here: http://www.linuxforum.com/linux-nfs/security.html