You badly need to read Oskar Andreasson's excellent IPtables Tutorial
available in several formats from
Bob Nichols AT comcast.net I am "rnichols42"
1. Req info on MANGLE-NAT-FILTER sequence.
2. solaris 7 for intel Configuration Assistant diskette
3. iptables v1.2.2: can't initialize iptables table `filter': Table does not exist
4. java path???
6. mangle, nat: what policy if I'm not using them?
7. getting SunOS 4.1.1 vi to work on a X11R5 xterm on a RS/6000
8. Where does netfilter nat reverse mangling take place?
10. iptables doesn't support mangle table
12. Filters, Filters, where are you Filters...