Manually bringing your interfaces up and down

Sun, 08/26/2012 - 19:23 -- jamie

Although your laptop will automatically bring your ethernet and wifi interfaces up and down for you, there are times when you will need to do that manually.

Debian provides two commands for this purpose:


Your ethernet interface is typically referred to as eth0 and your wifi interface is typically referred to as wlan0.

So, to bring down your ethernet interface, you can type:

ifdown eth0

And, to bring it backup, type:

ifup eth0

Using dig to query a DNS server

Sun, 08/26/2012 - 19:07 -- jamie

DNS (Domain Name System) translates from a domain name to an IP address.

This usually happens behind the scenes - if you type a domain name like into your web browser, your webrowser looks up the domain name, translates it into an IP address, queries the server responding to the IP address and then displays the web page - all the while, the actual IP address is hidden from you.

Sometimes, it's useful to manually do a lookup, particularly when you are debugging a problem that might be the result of a lookup failure.

Undestanding DHCP

Sun, 08/26/2012 - 18:58 -- jamie

On most linux computer, network interfaces (e.g. the network card that you plug an ethernet cable into or a wireless access card) are configured in a mostly automatic way. In other words, as soon as you plug in a cable, the network interface is activated and just works. Or, you click on a wireless access point that is in a drop down menu and indicate that you want to connect to it.

Behind the scenes DHCP is at work, ensuring that your interface gets a unique IP address.

Connecting to IRC for the training (and in general)

Wed, 08/08/2012 - 17:35 -- nat

As came up in our call, it would be great to have folks spend more time IRC, because that is where we (Ross and I) are every day, and because it is a tool that free software folks and techies use as a primary way to communicate.

Connection Details:
Channels/ Chatrooms: #poctechies and #mayfirst


From Roberto - installed Ubuntu on Laptop, but......????

Tue, 08/07/2012 - 16:25 -- Roberto

Yesterday I made a LiveUSB stick with Ubuntu and was able to start up a Windows laptop with Ubuntu, pretty cool stuff. Then I did an Ubuntu install on the laptop. I went the easy way and didn't worry about partitions for now, as per Ross' suggestion. I can always re-install it, etc.

So it reformatted the hard drive, got rid of Windows, etc., and then it told me that the installation was successful and to restart the computer. I restarted it and now all i'm getting is a dark screen with the blinking cursor. I tried putting in my password, but that didn't help.

Finally making some progress

Tue, 08/07/2012 - 01:38 -- Roberto

I was able to make my LiveUSB stick with Ubuntu today. I tested it on a Windows machine and was able to boot into Linux Ubuntu.

Tomorrow I'll deploy Linux on my soon to be Ex-Windows spare laptop. Hopefully it'll be easy. There's even an installer on the Ubuntu desktop.

Then once I'm back at my office (am in Califas now), I'll want to set up my office desktop computer and work laptop to dual boot with both Windows and Linux.

Exercise 1 - Creating a new user and group

Mon, 08/06/2012 - 18:13 -- ross

Hi All,

A couple of people asked for some exercises to get comfortable with using the command line, so here's exercise number 1. It should be fairly easy.

Goal 1: Create two different users one named "guest" and one named 'nohome' (You should also end up with a groups 'guest' and 'nohome'. The 'guest' user should have a home directory just like your regular user, but the 'nohome' user should not have a home directory.


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