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

How do I restart inetd service under Linux?

inetd is a daemon on Linux (BSD/Unix) systems that manages Internet services. inetd listens on all ports used by internet services such as FTP, POP3, and telnet. When a TCP packet or UDP packet comes in with a particular port number, inetd launches the appropriate server program to handle the connection. This uses memory more efficiently, as the other daemons do not run constantly.

Under old version of RedHat Linux you can restart inetd (login as root user):
# killall -HUP inetd

Note above command should work with almost any Linux distrobution.

New version of RedHat Linux (Fedora) comes with xinetd daemon, which can be restarted as follows:
# service xinetd restart

See also:

=> How to restart inetd under FreeBSD

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