让 Linux 更安全，第 3 部分: 加固系统

				
itvm06:~ # netstat -atup
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 *:5900                  *:*                     LISTEN      900/X
tcp        0      0 *:sunrpc                *:*                     LISTEN      509/portmap
tcp        0      0 *:x11                   *:*                     LISTEN      900/X
tcp        0      0 localhost:smtp          *:*                     LISTEN      881/master
tcp        0      0 localhost:x11           *:*                     LISTEN      12876/sshd
tcp        0      0 *:ssh                   *:*                     LISTEN      538/sshd
tcp        0      0 localhost:x11           *:*                     LISTEN      12876/sshd
tcp        0    144 server.example.com:ssh  client.example.co:35603 ESTABLISHED 12876/sshd
tcp        0      0 server.example.com:ssh  client.example:miva-mqs ESTABLISHED 11446/sshd
udp        0      0 *:sunrpc                *:*                                 509/portmap