Open up the following ports (tcp and udp) on the Fedora firewall. Do this either using the "Security Level" app in "System Settings" or using the command line iptables command (think it's in /sbin/):
111:tcp, 111:udp, 2049:tcp, 2049:udp, 4001:tcp, 4001:udp, 4002:tcp, 4002:udp, 4003:tcp, 4003:udp, 4004:tcp, 4004:udp