如何重置iptables规则

重置所有iptables规则，包括自定chain

# reset the default policies in the filter table.
iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT

# reset the default policies in the nat table.
iptables -t nat -P PREROUTING ACCEPT
iptables -t nat -P POSTROUTING ACCEPT
iptables -t nat -P OUTPUT ACCEPT

# reset the default policies in the mangle table.
iptables -t mangle -P PREROUTING ACCEPT
iptables -t mangle -P OUTPUT ACCEPT

# flush all the rules in the filter and nat tables.
iptables -F
iptables -t nat -F
iptables -t mangle -F

# erase all chains that's not default in filter and nat table.
iptables -X
iptables -t nat -X
iptables -t mangle -X