How do I restart Linux network service?

RedHat Linux command to reload or restart network (login as root user):

# service network restart
OR
# /etc/init.d/network restart

To start Linux network service:
# service network start

To stop Linux network service:
# service network stop

Debian Linux command to reload or restart network:
# /etc/init.d/networking restart

To start Linux network service:
# /etc/init.d/networking start

To stop Linux network service:
# /etc/init.d/networking stop

Ubuntu Linux user use sudo command with above Debian Linux command:
# sudo /etc/init.d/networking restart

To start Linux network service:
# sudo /etc/init.d/networking start

To stop Linux network service:
# sudo /etc/init.d/networking stop

Halt or stop linux firewall

A firewall is designed to help protect your computer from attack by malicious users or by malicious software (viruses that use unsolicited incoming network traffic to attack).

Also before you disable your firewall, you must disconnect your computer from all networks, including the Internet to avoid damage :D

You would like to Halt linux firewall or stop linux firewall (i.e. flush iptables rules). First login as root user.

Option A – If you are redhat Linux user type command:

If you are using Red Hat (RHEL) / CentOS / Fedora Core Linux, use the following command:

/etc/init.d/iptables stop

OR

service iptables stop

Option B – If you are Debian Linux user type following commands one by one

iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT