Installing GNS3 v0.8.2 on Ubuntu 12.04

Below are the basic steps for installing GNS3 0.8.2 on Ubuntu 12.04 and get it started. Video tutorials on  gns3 website .

(check out the three step installation for GNS3 v0.8.6 Installing GNS3 v0.8.6 on Linux)

Add hosts in GNS3 using VPCS on Ubuntu

The Virtual PC Simulator (VPCS) is a program that runs within Windows or Linux. It has limited functionality, but it allows pings and traceroutes. if you want to save memory and CPU cycles , VPCS is the application to go.
The VPCS can simulate up to 9 PCs.

When VPCS starts, it listens the ports from 20000 to 20008 and waits the
dynamips to connect, and sends the packets to the ports from 30000 to 30008.

More info in the GNS3 website here. From the official website go here.

1. Download VPCS 
use this link here

Installing GNS3 0.7.4 on Ubuntu 10.10 maverick

GNS3 is  an excellent tool  for graphical network simulator that allows simulation from simple to complex networks.A complementary tool for network engineers and people wanting to study for certifications such as Cisco as well as Juniper.

It can also emulate many Cisco IOS router platforms , PIX/ASA Firewalls and Juniper JunOS

The program is an open source, free program and  may be used on multiple operating systems, including Windows, Linux, and MacOS X.

 Check GNS3 documentation website for more details.

Check the old tutorial (for basic) and another for more advance users

My machine has Ubuntu 10.10 maverick (32-bit ).