Firewall Box Help

[jlong07]

Hello,

I am a complete newbie on linux. I just inherited the maintenance on a linux firewall and am unsure of how to check the settings. I am somewhat familiar with the workings of standard firewalls. Most of my experience is with built in firewalls on workgroup routers. I would realy appreciate it if someone could help me figure out where to look and what to check for. I know that the server is running red hat linux with the gnome gui. I have limited experience with bash because I have worked had to transfer files to and from a linux web server before. Any help that you can offer would be greatly appreciated.

 

[RhythmAce]

There are some software based firewalls for linux but I'm willing to bet you are running iptables/ipchains. You can read the man pages or check out this site.

http://www.netfilter.org

 

[thedaver]

Assuming you are running IPTables - the newest version of the filtering routines - you would be able to scan the firewall settings with:

iptables -n -L | more

The -L asks for a list, the -n asks for the numerical form of the IPs that may be controlled (eliminates DNS resolving for this task).

you may have NAT enabled too, do this

iptables -t nat -n -L | more

this requests the details for the nat table.



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http://www.surfinbox.com/shares/

 

[jlong07]

I found some documentation that mentioned something called webmin. I went to the address that it listed in a browser (

http://10.0.10.1:10000).

There was a web based administration utility. I poked around and saw things about the firewall, but it did not make a lot of sense to me. Is anyone familiar with this utility?

 

[RhythmAce]

Webmin handles two different firewalls, "Shorewalls" and "Linux Firewall" if it's the latter, then you have iptables. If none of what you see makes sense to you, then you might want to read up on iptables. If you have a particular question about iptables we are ready and willing to help.

 

[jlong07]

webmin says linux firewall. Do you have any reading material you can suggest for iptables?

 

[bluegroper]

Google for iptables howto
Turns up loads of stuff.
Google is your friend.