Aug

7

Forgotten Password – Reader Questions

August 7, 2009 | By: UbuntuLinuxHelp | 5 Comments
Posted in Q & A - Ubuntu

Rhonda, one of our readers asks:

"...I forgot my username and password on my ubuntu/Linux computer. How do I get back on? I have 2 computers just so you understand. One I use windows and the other I use ubuntu. I don't want to throw the computer away so any help would be greatly appreciated..."

I'm assuming this is the username to log into Ubuntu, not the a password for GRUB or the PC itself (that is a password set in the BIOS, which is requested when the PC is turned on).

First off, there's no need to throw the computer away, even if you are unable to garner the username or password; you can reinstall the OS.

The majority (if not all) of the Linux users I personally know, use their name as the username for regular login sessions and root as the username for administrative sessions. Ubuntu however facilitates sudo (or sudo su) via your regular username, if you'd like to perform administrative functions.

To obtain your username, Read more

Jul

15

Using The Host Object in Firewall Builder

July 15, 2009 | By: Vadim Kurland | Leave a Comment
Posted in How to...

                                                              

This entry is part 6 of 6 in the series Firewall Builder

This article continues the series of articles on Firewall Builder, a graphical firewall configuration and management tool that supports many Open Source firewall platforms as well as Cisco IOS access lists and Cisco ASA (PIX). Firewall Builder was introduced on this site earlier with articles Getting Started With Firewall Builder, Using Built-in Policy Importer in Firewall Builder, Using Firewall Object in Firewall Builder.

More information on Firewall Builder, pre-built binary packages and source code, documentation and Firewall Builder Cookbook can be found on the project web site at www.fwbuilder.org. Watch Project Blog for announcements and articles on all aspects of using Firewall Builder.

This article demonstrates how you can work with Host objects in Firewall Builder.

The Host Object

The host object in Firewall Builder is designed to represent real hosts in the network: workstations, servers, and any other network node with an address. Just like real hosts, the host objects have interfaces, representing different physical connections to the network. Most Internet hosts will have just a single (visible) interface with a single IP address. In that case the actual interface and its name do not matter. For most foreign hosts, Firewall Builder will assign an arbitrary name “interface1” to the hosts interface. By using a tree-like hierarchy of hosts -> interfaces -> addresses it is possible however to specify the exact address and/or interface of a host in the case when it does matter. Both interfaces and addresses are represented by objects, which are organized in a tree. Interface objects sit in the tree directly under the host, and the address objects are located under their interfaces. The interface object can have either one or multiple addresses. An example of a host with one interface with multiple addresses is shown in the screenshot below. Host “test server” has three virtual IP addresses that all belong to the same interface “eth0”.

In Firewall Builder, the host object is Read more

Jul

9

PGP – Setting Up Your Launchpad Key

July 9, 2009 | By: UbuntuLinuxHelp | 1 Comment
Posted in How to...

Granted, Launchpad might not be something newer Ubuntu users or less experienced users consider joining? However, I recently checked out the site and created my account. When I'm ready to create a couple packages, I can upload them to launchpad, where I or anyone in the community can access and use them, from anywhere. Additionally, part of the motivation is to give back to the community. When I started using Linux in earnest, I received a lot of community help, as such, this blog and the future Launchpad packages are a way of passing that help on.

On thing I noted was that Lauchpad uses PGP keys to help confirm that you really are you. That is, communications, agreements, etc. are really from you, the individual who signed up for the account. While I have not played with PGP in some time, I did manage to muddle my way through creating my key, adding it to the Ubuntu keyring and validating the fingerprint on Launchpad.

For those considering, here's a quick refresher. For those who are new, here's a "how to".

Creating and Using Your PGP Key / Fingerprint for Launchpad

If you don't already have it, you'll need to install GPA (Gnu Privacy Assistant):

sudo aptitude install gpa or use the Firefox APT link: apt:gpa

The install is very basic, now we'll need to generate a key:

gpg --gen-key

You'll see some options, but Read more

Jul

5

Installing a Web Server on Your Old Laptop

July 5, 2009 | By: UbuntuLinuxHelp | 1 Comment
Posted in Linux Projects - Hands On

                                                              

This entry is part 5 of 5 in the series Building a Web Developer / Designer PC

In an earlier post to this series, I talked about converting an old ancient IBM Thinkpad T22 Laptop into a proxy server (using Squid). While this did substantially improve my web surfing speed, it occurred to me that the laptop could be put to more use. One example is to install MediaWiki on it (to replace the Tomboy Notes application I use). In reality, I was surprised at the performance given the lack of hardware resources on this laptop, as such, I knew it could be put to more use.

One thing you'll notice in this post is that the command line does not use "sudo". This is because the last post configured the server to permit root logins via SSH. In fact, there is a lot of information in the last post that directly relates to (or effects) what we'll do in this one, again, please read it: Faster Internet With an Old Laptop – Ubuntu and Squid. Otherwise some of us might get a bit lost trying to complete the hands-on activities in this post. Also a reminder that this is an Ubuntu server 8.04 LTS, if using other versions of Ubuntu (or other Debian based distributions, you'll probably need to make a few adjustments).

In order to make this old laptop even more useful, in addition to the previously installed Squid proxy server, we're going to add an Apache webserver with PHP, MySQL database server and Mail server (SMTP/POP3). The mailserver is just for the future in the event it's needed or any PHP based package requires it (so you can skip that if you don't need it). More importantly, Apache and MySQL are needed so I can successfully install and use MediaWiki.

First SSH into your server. The command for me is:

ssh root@squid.localdomain (You'll need to substitute the hostname you chose for your server).

Let's get some packages for  compiling, zip, perl, ssl, certificates and so on. Remember, because you logged in as root, you don't have to Read more

Jul

2

Using Firewall Object in Firewall Builder

July 2, 2009 | By: Vadim Kurland | 1 Comment
Posted in How to...

                                                              

This entry is part 5 of 6 in the series Firewall Builder

This article continues the series of articles on Fireall Builder, a graphical firewall configuration and management tool that supports many Open Source firewall platforms as well as Cisco IOS access lists and Cisco ASA (PIX). Firewall Builder was introduced on this site earlier with articles Getting Started With Firewall Builder and Using Built-in Policy Importer in Firewall Builder.

More information on Firewall Builder, pre-built binary packages and source code, documentation and Firewall Builder Cookbook can be found on the project web site at www.fwbuilder.org. Watch Project Blog for announcements and articles on all aspects of using Firewall Builder.

Firewall Builder supports variety of object types, both simple such as address, network, host, or IP, TCP, UDP and ICMP services, as well as more sophisticated such as Firewall, Host, Address table, DNS name, User service. Firewall object is central to the program and is in the focus of this article.

General Description

A firewall object is designed to represent a real firewall device in your network. This firewall object will have interface and IP address objects that mirror the real interfaces and IP addresses of the actual device. In addition, the firewall object is where you create the access policy rule sets, NAT rule sets, and routing rule sets that you assign to your firewall device.

By default, a firewall has one Policy rule set, one NAT rule set, and one routing rule set. However, you can create more than one rule set using branching rules (for firewalls that support them). On the other hand, you don’t have to populate all the rule sets. You can, for example, create a Policy ruleset and leave the NAT and Routing rule sets empty. We explains more about policies and rule sets below.

To speed up the creation of a firewall object, Firewall Builder has a wizard that walks you through creating the object. The wizard has three options for creating a firewall object:

  • From a template: Firewall Builder comes with several pre-defined templates. You can use these to create a firewall that is close to your configuration, the modify it to fit your needs. This method is demonstrated in the "Getting Started with Firewall Builder" here or here.
  • Manually: You can provide interface IP address, subnet mask, gateway, and other parameters manually. You can add this information when you create the firewall, or you can add it later.
  • Via SNMP: Firewall Builder uses SNMP queries to learn about the network.

Creating Firewall Object Manually

To start the firewall object creation wizard, right-click the Firewalls folder in the User tree and select New Firewall.

The first page of this wizard is displayed.

New Firewall Wizard Read more


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