I'm confused as to what protocols 50 and 51 are.
-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
The '-p' option is not for a network port but for a protocol. I've never heard of 50 and 51 protocols.
What are they? What are they used for?