tlug: INPUT chain

["Subba Rao" <subb3@example.com>]

My INPUT chain has the ACCEPT policy, on my linux gateway. This system has
2 interfaces. One is a modem interface (Internet) and the other is a ethernet interface (Intranet).

EXERCISE

For the modem interface, I setup the following rules,

$ ipchains -A input -i ppp0 -p 21 -j DENY
$ ipchains -A input -i ppp0 -p 23 -j DENY
$ ipchains -A input -i ppp0 -p 80 -j DENY

My goal in this exercise is to prevent outside telnet, ftp and www access
to my gateway.

RESULTS

>From a remote machine(from a different LAN on the Intranet), I can still access these service.

What is wrong with the above rules? What am I doing wrong?

Thanks you in advance for your input.

Subba Rao
subb3@example.com
==============================================================
Disclaimer - I question and speak for myself.

http://pws.prserv.net/truemax/
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