How to Restart Network Interface in Linux

Restart Network Interface Using Command Lines in Linux (generic method)

The procedure to to turn off eth0 interface is as follows. Run:
# ifdown eth0
To turn on eth0 interface run:
# ifup eth0
See ip address info using the ip command:
# ip a show eth0

Debian / Ubuntu Linux restart network interface

To restart network interface, enter:
sudo /etc/init.d/networking restart
To stop and start use the following option (do not run them over remote ssh session as you will get disconnected):
sudo /etc/init.d/networking stop
sudo /etc/init.d/networking start
Debian/Ubuntu Linux with systemd, run:
$ sudo systemctl restart networking

Redhat (RHEL) / CentOS / Fedora / Suse / OpenSuse Linux – Restart network interface in Linux

To restart network interface, enter:
# /etc/init.d/network restart
To stop and start use the following option (do not run them over remote ssh session as you will get disconnected):
# /etc/init.d/network stop
# /etc/init.d/network start
Fedora/RHEL/CentOS/Suse Linux with systemd, run:
$ sudo systemctl restart network

Slackware Linux restart commands

Type the following command:
/etc/rc.d/rc.inet1 restart
You can take down or restart particular interface such as eth1 as follows:
# /etc/rc.d/rc.inet1 eth1_restart
# /etc/rc.d/rc.inet1 eth1_start ### start eth1 ###
# /etc/rc.d/rc.inet1 eth1_stop ### stop eth1 ###

How to see status of network/networking service

Run command:
$ sudo systemctl status network #CentOS/RHEL/Fedora/Suse
$ sudo systemctl status network #Debian/Ubuntu
Sample outputs:

* wicked.service - wicked managed network interfaces
   Loaded: loaded (/usr/lib/systemd/system/wicked.service; enabled; vendor preset: disabled)
   Active: active (exited) since Sat 2018-01-13 06:40:25 UTC; 1 weeks 3 days ago
  Process: 93 ExecStart=/usr/sbin/wicked --systemd ifup all (code=exited, status=0/SUCCESS)
 Main PID: 93 (code=exited, status=0/SUCCESS)
    Tasks: 0 (limit: 512)
   CGroup: /system.slice/wicked.service
 
Jan 13 06:40:10 opensuse systemd[1]: Starting wicked managed network interfaces...
Jan 13 06:40:25 opensuse wicked[93]: lo              up
Jan 13 06:40:25 opensuse wicked[93]: eth0            up
Jan 13 06:40:25 opensuse systemd[1]: Started wicked managed network interfaces.

To see info about ip address run:
# ifconfig -a
OR
# ip a
# ip a show
# ip a show eth1

How to restart the networking service on Gentoo

Run the following for eth0:
# /etc/init.d/net.eth0 restart