I would like to block entire traffic from SLES server to one host in my network. I've tried doing it it many ways but communication still works. For example I added two lines:
iptables -A INPUT -d 192.168.0.253 -p tcp -j REJECT
iptables -A OUTPUT -d 192.168.0.253 -p tcp -j REJECT
But it doesn't work. How to solve this problem?