Linux administrator needs a list of networking commands essential
for effective server use.
This article provides a summary of the
most important or frequently used commands, and offers some tips for
ensuring your server runs smoothly.
Please keep in mind that these
tips assume you already have a configured Linux
hostname and IP,
with a working network card and connection.
short but quite useful command allows you to check your network card for
connectivity and review your IP address and host network information.
Although I tend to use other commands more frequently, arp
is useful when I want to very quickly check status on my network
The host command is something I use very regularly to check either the hostname of a specific server when I have the IP address, or the IP address when I have a specific hostname. The primary function of the host command is to enable a quick lookup of DNS server information. But don't underestimate the power of this command. The host command allows you to perform many different queries using the -t option. For instance, you can use the -t with TOC to specify that you wish to lookup a host geographical location:
host -t LOC hostname
(replace hostname with the fully qualified domain such as reallylinux.com)
ifconfig command allows
you to check and configure your server's network cards, assigning IP,
DNS, and Gateway addresses. For example, to assign a specific IP
address for the eth0 network card, you can use:
to 10.1.1.1 with an actual IP address)
You can get more details on this type of command on our Server Administration webpage.
using the plain ifconfig
command shows you the details of all the existing configured network
cards and network interfaces. You can get more information about it
in the reallylinux.com administrative command list.
Using ifconfig is a very good way to check that your network
hardware is working properly.
netstat command offers you
a simple way to review each of your network connections and open
sockets. I frequently use the netstat
with the head
command to review the top few lines of output, which are helpful when
performing web server administration. For example:
by including the -r
option, you get a very good summary of all of the network routing
basic network administration is effective without the ping
command. I use it for testing server configuration and checking
status. The ping command
basically sends test packets to a specific server and checks if
there is a response. The command is very helpful when trying to
determine where a connectivity error originates.
the 10.1.1.1 with the specific IP address of the server you wish to
you run the command, please remember to press Ctrl
and C to stop the
process. More details are available in our administrative
is a useful command and should be one of your first tests when a
network failure occurs. If it works but for instance HTTP connections
don't, then you know that the server network connectivity is correct,
so the fault may instead be with the HTTP daemon or a problem with
firewall settings. You
can get more information about it in the reallylinux.com
administrative command list.
More importantly, if even the ping
command fails to work, you know that there is a more significant
server connectivity issue. It is a very fast way to check servers,
command allows you to check the Internic database for proper
hostnames. This is very handy when you are trying to trace back an
IP address to a specific hostname, or the reverse. I often use it
when troubleshooting connectivity between hosts and checking whether
the problem is a host configuration error or an actual physical
connectivity error. The most commonly used version of the command
the 10.1.1.1 with a specific server IP)
-f option forces the
command to skip any cache that may have stored the host state, and
instead goes to the actual server to perform a lookup and verify its
useful variation of the command, especially for trying to identify
port problems is:
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