Use netstat in Linux to view the network status and port status.

Use netstat in Linux to view the network status, port status (to), and linuxnetstat

Turn: http://blog.csdn.net/guodongdongnumber1/article/details/11383019

 

In linux, netstat is generally used to view system port usage.

The netstat command is a very useful tool for monitoring TCP/IP networks. It can display the route table, the actual network connection, and

The netstat command displays network connection, route table, and network interface information, allowing you to know which network connections are currently in operation.

The common format of this command is:


Netstat [Option]

The meanings of the options in the command are as follows:

-A displays all sockets, including those being monitored.

-C is re-displayed every one second until the user interrupts it.

-I displays information of all network interfaces in the same format as "ifconfig-e ".

-N is replaced by a network IP address to show network connection conditions.

-R displays the core route table in the same format as "route-e ".

-T shows the TCP connection status.

-U: displays the connections of the UDP protocol.

-V: displays ongoing work.

1. netstat-an | grep LISTEN
0.0.0.0 is a service provided by each IP address, indicating which IP address is the service bound to that IP address.

2. netstat-tln
Used to view linux port usage

3./etc/init. d/vsftp start
Is used to start the ftp port ~!

4. netstat
View the connected service port (ESTABLISHED)

5. netstat-
View All service ports (LISTEN, ESTABLISHED)

6. sudo netstat-ap
View All service ports and display the corresponding service program name

7. nmap <scan type> <scan parameters>
For example:
Nmap localhost

Nmap-p 1024-65535 localhost

Nmap-PT 192.168.1.127-245

When we use netstat-apn to view network connections, we will find a lot similar to the following:

Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name

Tcp 0 52 218.104.81.152: 7710 211.100.39.250: 29488 ESTABLISHED 6111/1

It indicates that port 7710 is opened on this server. Which program does this port belong? We can use the lsof-I: 7710 command to query:

COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME

Sshd 1990 root 3u IPv4 4836 TCP *: 7710 (LISTEN) 54com.cn

In this way, we know that port 7710 belongs to the sshd program.