:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
:INPUT ACCEPT [0:0]
# INPUT ACCEPT
:FORWARD ACCEPT [0:0]
# FORWARD ACCEPT
:OUTPUT ACCEPT [0:0]
# OUTPUT ACCEPT
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# ，ESTABLISHED： 。RELATED： 。
-A INPUT -p icmp -j ACCEPT
# ICMP
-A INPUT -i lo -j ACCEPT
#
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
# TCP 22
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
# INPUT FORWARD 。 host prohibited 。