Ethical Hacking

Learn to find vulnerabilities before the bad guys do! Gain real world hands on hacking experience in our state of the art hacking lab. Course designed and taught by expert instructors with years of penetration testing experience. 12 student maximum in every class. Certification attempt included in every package.
Computer Forensics Training at InfoSec Institute

Gain the in-demand skills of a certified computer examiner, learn to recover trace data left behind by fraud, theft, and cybercrime perpetrators. Discover the source of computer crime and abuse at your organization so that it never happens again. All of our class sizes are guaranteed to be 12 students or less to facilitate one-on-one interaction with one of our expert instructors.




Network Security Firewalls
[Top] [All Lists]

IPFW and ICMP

Subject: IPFW and ICMP
Date: Wed, 29 Mar 2006 10:33:36 -0800 (PST)
I am using an IPFW firewall and only allowing ICMP in
one direction.  Example:

ipfw -q add 00501 allow icmp from 192.168.1.1 to any
out via fxp1 keep-state

The problem that I have is when I send icmp packets
from 192.168.1.1 to 192.168.5.2, the icmp packet
works, but the system on the other end can now ping
192.168.1.1.

What is happening is that the firewall is not able to
tell the differrence between an icmp-echo request and
an icmp echo reply.

Is there any way to make force the firewall to keep a
stateful connection while only allowing the initiation
of the icmp packet come from the host requesting it?

Thanks


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

<Prev in Thread] Current Thread [Next in Thread>