GNS3: Add Qemu Host (MicroCore)

December 14th, 2010 by http://www.brainbump.net

This write-up will explain Qemu Image use in GNS3 . Qemu Host image can be either CLI ( Microcore ) or GUI (Tinycore).Its basically a small linux image which can be used for performing some basic connectivity tasks e.g telnet, ssh, iptables, route, tcpdump and IPv6 support.

This tutorial will walk you through step by step for setting up Qemu Host image in GNS3

MicroCore Setup Instructions:


1.Set Qemu Host in GNS3 Preferences.
Edit -> Preferences -> Qemu -> Qemu Host

2.Setup Network Topology

3. Start & Configure R1 for Basic Connectivity (IP address etc.)

4. Start & Configure Qemu Host for Basic Connectivity (IP address etc.)

5. Test Connectivity between R1 & Qemu1

6. Enable R1 for telnet & ssh connections:

7. Remotely manage Router from Qemu Host :

8. Add Default Route / Gateway to  Qemu Host :

9. Use Qemu Host built-in tools e.g tcpdump & iptables for advanced testing:
tcpdump

IPtables

10. Finally , save all your configs  :

In order to make your configuration changes persistent so that they get automatically loaded upon reboot, use following commands:
vi /opt/bootlocal.sh
Add your configuration line by line & save the file (:wq!)

hostname Qemu1
ifconfig eth0 192.1.12.2 netmask 255.255.255.0 up
route add default gw 192.1.12.1
iptables -A INPUT -p tcp –dport telnet -j ACCEPT
iptables -A INPUT -j DROP

/usr/bin/filetool.sh backup
That’s all !
Software Version Used:

• GNS3 Version : v 0.7.3
• Microcore Version : 2.11.5
• Tinycore Version : 2.11.5
• IOS Image : c3745-adventerprisek9-mz.124-15.T13.bin

->For help using IPtables , refer to this guide
->Download Qemu Microcore / Tinycore Linux binary images from the following link: http://www.gns3.net/download