Recently we had a need to open a port on our CentOS6
system. We followed the instructions given on an old stackoverflow post i.e.
iptables -A INPUT -m state --state NEW -p tcp --dport ?port-num? -j ACCEPT
/etc/init.d/iptables restart
These instructions worked quite well. However, now we want to close the port. Naturally we tried
iptables -A INPUT -m state --state NEW -p tcp --dport ?port-num? -j DROP
/etc/init.d/iptables restart
However, we are finding that the port is still open. As per the man page of iptables (e.g. here)
DROP
should have done the trick.
question from:
https://stackoverflow.com/questions/66046990/closing-a-port-on-centos6 与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…