RedHat Linux firewall tester
 

:(
hello :
i have made a firewall by ipchains.
but now i want to test it and i must do it myself .
so i need the related documents, tools, ......
please
thanks you
your david
Nov 15,2001

Re: RedHat Linux firewall tester
 

i was going 2 recommend this thread:
http://www.linuxquestions.org/questi...&threadid=8694

but seeing that u want 2 do it u'rself look for a tool called nmap.

I'll go along with lsof's answer.

Install nmap on a system that's external to your firewalled system.
If not it's hard to confirm your really seeing what others would get.

Then test for open ports using the following commands.

nmap -sT -d -e eth0 -S 202.34.181.234 -g 53 -P0 -n -r -T4 -p 1-10000 -O 170.23.45.1
nmap -sT -d -e eth0 -S 202.34.181.234 -g 20 -P0 -n -r -T4 -p 1-10000 -O 170.23.45.1

-e eth0 (make this your outgoing internet connection)
-S 202.34.181.234 (make this the internet of the nmap system)
O 170.23.45.1 (make this your IP address of the system your testing)
-T4 (change this to T3 then T2 if your ping rate to the system is higher then 200ms etc etc)

Don't try to scan anyone other then your firewall with these settings as it's not very stealthy, but it will find open connection for you.

Next step is to fake SYN flags and random ack numbers with the following scan.

nmap -sA -d -e eth0 -S 202.34.181.234 -g 53 -P0 -n -r -T4 -p 1-10000 -O 170.23.45.1

if you get filtered ports then they are not open, any port that doesn't respond is open but filtered with stateful filtering.

use "man nmap" for more info.

/Raz