[MCZOFT]

One more thing /


If you just want to block access to one port from an ip xxx.xxx.xxx.xxx to port xxxx then type command:

PHP код:

iptables -A INPUT -s xxx.xxx.xxx.xxx -p udp --destination-port xxxx-j DROP 


The above rule will drop all packets coming from IP xxx.xxx.xxx.xxx to port mail server port xxxx.

But the DROP will not be inmediate and may need a server restart if there are already connections from the offending IP.

This scenario is common with script kiddies trying to DDOS your server.