Blocking https port

[Shafiq]

I want to block https (port 443) traffic for my LAN users using iptables, please guide? I am using RedHat 9.
Thank you,

[anomie]

The rule inserted into the OUTPUT chain would look something like:

# iptables -I 1 OUTPUT -p tcp --dport 443 -j REJECT

I used the REJECT jump target because your LAN users probably won't appreciate a black hole.

If you're providing nat, you'll need to adjust accordingly.

P.S. You might want to look into squid as an alternative to restricting http/s traffic via iptables.