网络监听的端口分析：
[root@localhost ~]# netstat -tulnp
### -t tcp
### -u udp
### -l, --listening display listening server sockets
### -n, --numeric don't resolve names
### -p, --programs display PID/Program name for sockets
Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 1222/rpcbind tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1542/sshd tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN 1335/cupsd tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1636/master tcp 0 0 0.0.0.0:58182 0.0.0.0:* LISTEN 1287/rpc.statd tcp 0 0 0.0.0.0:5672 0.0.0.0:* LISTEN 1679/qpidd tcp 0 0 :::111 :::* LISTEN 1222/rpcbind tcp 0 0 :::22 :::* LISTEN 1542/sshd tcp 0 0 ::1:631 :::* LISTEN 1335/cupsd tcp 0 0 ::1:25 :::* LISTEN 1636/master tcp 0 0 :::39258 :::* LISTEN 1287/rpc.statd udp 0 0 0.0.0.0:60196 0.0.0.0:* 1287/rpc.statd udp 0 0 0.0.0.0:68 0.0.0.0:* 1260/dhclient
