I have recently installed Redhat 4.2 and am attempting to set up IP Masquerading. The firewall portion of ipfwadm seems to work fine, but when I try to do anything with the masquerading portion, I get the error 'setsockopt failed: Invalid argument'. I am entering commands straight out of the FAQ's (a number of different versions) so I'm not convinced that it's something wrong in my commands. The kernel has been compiled with options as per the FAQ and the modules have been installed. What little thing am I missing?
addendum: ipfwadm -M -l returns 'cannot open /proc/net/ip_masquerade'. (since that file doesn't exist I suppose)