iptables doesn't work as expected
I want to use the command below to block port 23 for all IPs except one 192.168.1.11:
#iptables -A INPUT ! -s 192.168.1.11 -p tcp --dport 23 -j DROP
after I am done and restart iptables, all other IPs can still telnet it. not sure if anyone knows what my problem is?