Linux netstat Command: Network Connections, Routes and Statistics

The netstat command in Linux is part of the old legacy Net-Tools package and displays network connections, routing tables, interface statistics, etc. It was elegantly replaced by the "ss" command.

Examples:

# netstat -anpActive Internet connections (servers and established)Proto	Recv-Q	Send-Q	Local Address	Foreign Address	State 	PID/Program nametcp	0	0 0.0.0.0:3306	0.0.0.0:*	LISTEN	981/mysqldtcp	  0 0 	0.0.0.0:8080	0.0.0.0:*	LISTEN	24929/mini-apache:tcp	0	0 0.0.0.0:8888	0.0.0.0:*	LISTEN	2160/httpdtcp	0	0 0.0.0.0:3128	0.0.0.0:*	LISTEN	1994/(squid)tcp	0	0 127.0.0.1:953	0.0.0.0:*	LISTEN	935/named

In this example the netstat command lists all open connections and processes that are listening for connections and to which process they belong. The "-p" option only shows the programs "owning" the connections to root.

The -i option provides a volume statistic of data traffic on each interface:

$ netstat -i
Tabela de Interfaces do Kernel
Iface      MTU    RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0      9001 34849988      0      0 0      30552900      0      0      0 BMRU
lo       65536  4407543      0      0 0       4407543      0      0      0 LRU

The "-r" option shows the routing table, much like the route command:

$ netstat -rnTabela de Roteamento IP do KernelDestino         Roteador        MáscaraGen.    Opções   MSS Janela  irtt Iface0.0.0.0         172.30.0.1      0.0.0.0         UG        0 0          0 eth010.8.0.0        10.8.0.2        255.255.255.0   UG        0 0          0 tun010.8.0.2        0.0.0.0         255.255.255.255 UH        0 0          0 tun0169.254.169.254 0.0.0.0         255.255.255.255 UH        0 0          0 eth0172.30.0.0      0.0.0.0         255.255.255.0   U         0 0          0 eth0

netstat also provides network interface statistics with the "-s" option:

$ netstat -sIp:    8871 total packets received    0 forwarded    0 incoming packets discarded    7997 incoming packets delivered    5023 requests sent out( ... )

Learn much more about Linux in our online course. You can enroll here. If you already have an account, or want to create one, just log in or create your user here.

Liked it? Share