OS X like Stealth Mode

phpinfo · 02-11-2009, 05:37 PM

OS X Leopard Server has firewall options for TCP and UDP stealth mode, which does things like block port scans etc. If you try to do a port scan you won't get any results.

I am using RHEL4. Is there a way to setup iptables in similar fashion with "stealth mode" and block port scans etc.?

win32sux · 02-11-2009, 05:52 PM

Quote:

Originally Posted by phpinfo

OS X Leopard Server has firewall options for TCP and UDP stealth mode, which does things like block port scans etc. If you try to do a port scan you won't get any results.

I am using RHEL4. Is there a way to setup iptables in similar fashion with "stealth mode" and block port scans etc.?

Yes. If you only send inbound packets in states RELATED and ESTABLISHED to ACCEPT (and all others to DROP), then that is considered "stealth mode". Example:

Code:

iptables -P INPUT DROP
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT