OS X like Stealth Mode - iptables ??

[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.?

[GNU-Fan]

Wow, "Stealth Mode". Nice marketing buzzword.
If you do not want a port reachable, you should close the application that opens it.
And just not responding to ping requests doesn't make you invisible by any means.

That said, you can of course block all ICMP requests.
Linux Iptables allow or block ICMP ping request

and you can "block" all ports except the ones explicitly named by you.
Iptables - Noah.org

[Lazydog]

This is not hard to setup and in RH this is the default setup.
Just start iptables and you are done.

Here is a TUTORIAL for Iptables.

[MetalheadGautham]

Would be great if there was a simple BASH script (to be run as root via sudo perhaps) to turn this off and on, on-the-fly.

[Lazydog]

To start the firewall

 service iptables start

To stop the firewall

service iptables stop

To reset the firewall

service iptables restart