iptables -nvL 查看防火墙是否关闭：如下代表防火墙没关闭。

iptables -nvL 查看防火墙是否关闭：如下代表防火墙没关闭。

Chain INPUT (policy ACCEPT 0 packets, 0 bytes)

pkts bytes target prot opt in out source destination

4157 1985K RH-Firewall-1-INPUT all -- * * 0.0.0.0/0 0.0.0.0/0

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)

pkts bytes target prot opt in out source destination

0 0 RH-Firewall-1-INPUT all -- * * 0.0.0.0/0 0.0.0.0/0

Chain OUTPUT (policy ACCEPT 2338 packets, 1850K bytes)

pkts bytes target prot opt in out source destination

Chain RH-Firewall-1-INPUT (2 references)

pkts bytes target prot opt in out source destination

1521 1766K ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0

0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 icmp type 255

0 0 ACCEPT esp -- * * 0.0.0.0/0 0.0.0.0/0

0 0 ACCEPT ah -- * * 0.0.0.0/0 0.0.0.0/0

34 5274 ACCEPT udp -- * * 0.0.0.0/0 224.0.0.251 udp dpt:5353

0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 udp dpt:631

0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:631

415 25587 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED

1 52 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22

2186 188K REJECT all -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited

正常情况如下：

iptables -nvL

Chain INPUT (policy ACCEPT 770 packets, 52869 bytes)

pkts bytes target prot opt in out source destination

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)

pkts bytes target prot opt in out source destination

Chain OUTPUT (policy ACCEPT 737 packets, 108K bytes)

pkts bytes target prot opt in out source destination

[root@localhost ~]#