Linux netstat Command- statistics of network protocol, interfaces, sockets, ports, device connections informations, cmd Example

Tutorials

Linux-commands

Topic

What is Linux netstat Command?

Explanation

netstat COMMAND:
      nestat command displays statistics information and current state of network connections, protocol, ports/ sockets and devices.

SYNTAX:
  The Syntax is
     netstat [options]

OPTIONS:

-s	dispalys statics information about protocols.
-i	dispalys statistics information about the network interface.
-r	diplays routing table.
-c	displays statistics information and updates every second.
-l	displays information about all sockets that are in listening state.
-a	displays information about all sockets that are in listening and non-listening state.
-p	displays information about sockets with ProcessName and PID.

EXAMPLE:

To get statistics of network connections:

netstat

The sample output of above command:

Active Internet connections (w/o servers)
Proto	Recv-Q	Send-Q	Local Address	Foreign Address	State
tcp	0	0	vhost:32803	LocalHost:smtp	TIME_WAIT
tcp	0	0	vhost:32803	google.com:http	ESTABLISHED

Where,
Proto	-Specifies the Protocol used for connection.
Recv-Q	-Specifies the Number of Bytes which are not recevied.
Send-Q	-Specifies the Number of Bytes not send to destination.
Local Address	-Specifies the local or source address and port.
Foreign Address	-Specifies the destination address and port.
State	-Specifies the current state of conection to the socket. ESTABLISHED - Connection is Established. TIME_WAIT - Waiting to receive packets. LISTEN - Listening to establish connection.

To Get Statistics of Protocols:
```
netstat -s
```
The Sample output of above command:

IP:

5193 incoming packets delivered
4813 requests sent out

Tcp:

4033 segments received
4813 segments send out

Icmp:

41 ICMP messages received
178 ICMP messages sent
To Get statistics of Network Interface:
```
netstat -i
```
The sample output of above command:

Kernel Interface table

Iface MTU Met RX-OK RX-ERR TX-OK TX-ERR Flg

eth0 1500 0 1308 0 1345 0 BMRU

This is the statistics information of Ethernet Card[eth0].

netstat Linux Commands