Simple question about firewalls

ALInux · 11-27-2005, 09:08 AM

I have a simple router setup, using the following

eth0 = local
eth1 = external

I want to be able to ftp and ssh the router from the internet so I set the rules to accept those two and then drop everything else on eth1.

What about eth0, I have a local webserver on port 8080 should I use the same procedure ...I mean block everything exept port 8080.

Note: I used my linux box before with only one interface , but now Iadded a second computer and I want to setup my firewall. I will setup NAT later

peter_robb · 11-27-2005, 09:19 AM

The only controls you will need on eth0 are outgoing restrictions.. eg blocking access to external services..

For users on eth0 they will need SNAT on eth1 to be able to access the internet, and make sure ip_forward is on.

ALInux · 11-27-2005, 09:24 AM

Ok thanks I got that...another question if you do not mind....do I need to setup established and state for a state firewall....or can I do it without them......

peter_robb · 11-27-2005, 10:02 AM

Usually you need to allow ESTABLISHED & RELATED if you have a DROP policy. It saves many port by port rules.
NEW connections have to be handled one by one in the rules.

ALInux · 11-27-2005, 02:08 PM

Ok thanks for the help..Ive read a couple of tutorials...but there are things that can only be deduced through discussions with experienced users like you...
Thanks again