Before doing general cleaning iptables make sure you know how to configure it according to your needs
Clear CentOS/ Debian iptables rules .
The following command lines in the following order:
1. iptables -P INPUT ACCEPT
2. iptables -P FORWARD ACCEPT
3. iptables -P OUTPUT ACCEPT
4. iptables -F
5. iptables -X
6. iptables -t nat -F
7. iptables -t nat -X
8. iptables -t mangle -F
9. iptables -t mangle -X
iptables –help :
-P (policy) = chain target
–Flush -F [chain] Delete all rules in chain or all chains
-table -t table table to manipulate (default: `filter ')
-X [chain] Delete a user-defined chain