Display Your Current Network Configuration

This is really useful and you will use this bit of information quite often.  I know I keep repeating it, but knowing is half the battle.  Understanding what you are looking at is key in this industry.

Below I will show you how to get a glance at your current networking configuration and explain some of the important stuff in plain English.  Even if you are not familiar with computers this should open up a few new doors for you.

  1. List your current network configuration in Linux
    2. $ ifconfig
eth0      Link encap:Ethernet  HWaddr 08:00:27:b3:1b:6c
 inet addr:192.168.1.113  Bcast:192.168.1.255  Mask:255.255.255.0
 inet6 addr: fe80::a00:27ff:feb3:1b6c/64 Scope:Link
 UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
 RX packets:55 errors:0 dropped:0 overruns:0 frame:0
 TX packets:51 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:7032 (7.0 KB)  TX bytes:7096 (7.0 KB)
 Interrupt:19 Base address:0xd020
 
lo        Link encap:Local Loopback
 inet addr:127.0.0.1  Mask:255.0.0.0
 inet6 addr: ::1/128 Scope:Host
 UP LOOPBACK RUNNING  MTU:16436  Metric:1
 RX packets:0 errors:0 dropped:0 overruns:0 frame:0
 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:0
 RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

OK, so what does it all mean.  Well, for starters ‘eth0′ is the how the computer refers to your very first network card.  If you had two network cards you would also see a entry here for ‘eth1′.  Remember, computers like to start with the number zero!  Not the number one like humans like to.

The ‘HWaddr’ is the network card’s MAC address ( Media Access Control ), a unique hexadecimal identifier.  Every network card in the world has its own individual MAC address.  It has several purposes like who manufactured the card and the hardware address.  Network cards can have their MAC addresses changed ( a method called spoofing ) but for the basic user, you do not need to worry yourself with this.  If you want to know more about MAC addresses you can find that information via Wikipedia.

The ‘Bcast’ is the broadcast address.  A address your computer can send information to if it needs to send a signal to everything on the network instead of sending it to each and every address on the network one by one.  Kinda like how if you have something to say to a crowd of people versus talking to each individual person one by one.

The ‘Mask’ is the Subnet Mask.  It allows for a more simplistic description of your network.  Similar to how your home address must have a zip code to identify the city of the address.  People in other cities could have the same exact address, but are unique by the different zip code.

The ‘inet addr’ is the computers IP address (also known as the TCP/IP Address, meaning Transmission Control Protocol / Internet Protocol ) that it is currently configured with.  This is basically your computer’s address (like a house has a address in a neighborhood) on the network.

Everything else can be ignored for now as you do not need to know what it is or what it means to be able to configure a regular network card.

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