How To Emulate Switches

These methods are not guaranteed to emulate 100% of the switching functions. However, they provide more than 90% of the switching features most network engineers need for CCNA/CCNP preparation.

There are many options:

  • GNS3 routers with NM-ESW16 modules
  • GNS3 with Virtual IOS Layer 2
  • GNS3 with IOU L2 images
  • Unified Networking Lab

First, read this post to add IOS images.

GNS3 routers with NM-ESW16 modules

A router can be equipped with a NM-ESW16 module to fulfill the functions of an EtherSwitch Module. This module provides many layer 2 switch functionnalities.

nm-16esw Etherswitch Module

The only type of routers that supports the NM-16ESW EtherSwitch module and is also supported by GNS3 is the Cisco 3725 router.

 GNS3 with Virtual IOS Layer 2

Nathan Ash has written a clear tutorial for this.

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_46_57

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_47_03

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_47_12

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_47_25

For the RAM value, choose something that’s higher than 380 MB then click Next.

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_47_44

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_47_52

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_48_14

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_48_22

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_48_38

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_48_49

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_49_03

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_52_44

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_52_59

GNS3-qemu-VM-vIOS-l2-2015-11-08 19_53_47

One thing to mention though. Make sure to choose the right version of Qemu binary when you add the vIOS-L2 image. I have a Windows 7 64 bits and I first used the default Qemu binary and I got a Network Connection failure message. I thought it was a firewall issue at first. But I realized it was something with the Qemu binary and I changed the setting to qemu-system-x86-64w.exe

vIOS-GNS3-VM-qemu-1

vIOS-GNS3-VM-qemu-2

GNS3 with IOU L2 images

This technique uses a virtual IOS for Layer 2 and run it on Qemu. Then GNS3 interfaces with Qemu to manipulate the virtual IOS.

You need to have a vIOS-L2 Vmware image (vIOS-l2.vmdk) for this technique.

Here are a couple of great resources:

Download Virtualbox.

Download The GNS3 IOU VM.

Follow the steps in this blog.

When trying to install VirtualBox, you may encounter the error “Windows Installer Service could not be accessed..” then I recommend you check some of the workaround mentioned in this link.

One thing I’d like to cite is to check your GNS3 client version:

GNS3-2015-11-08 19_32_56

GNS3-2015-11-08 19_33_00

My current GNS3 client version is 1.3.11. Why is this important? Because the GNS3 client version must match the GNS3-server version that is on the VirtualBox VM. Otherwise, you’ll get an error like this:

=> Error while creating project: Client version 1.3.11 differs with server version 1.3.0

The solution is to upgrade the server inside the IOU VM (credit to Julien Duponchelle):

  •  Stop the VM in VirtualBox, either from Virtualbox or from the VM command line

2015-11-08 17_03_44-GNS3 IOU VM [En fonction] - Oracle VM VirtualBox

  • Go the virtualbox settings and change the network adapter from host only to nat

2015-11-08 17_01_39-Oracle VM VirtualBox - Gestionnaire de machines

2015-11-08 17_01_52-GNS3 IOU VM - Paramètres

  • Boot the vm

2015-11-08 17_02_03-Oracle VM VirtualBox - Gestionnaire de machines

  • Upgrade the GNS3 server version with the PIP command. For example, if your GNS3 client version is 1.3.11, then the GNS3-server version must also be 1.3.11, and we issue the follwing command on the VM:
 pip3 install gns3-server==1.3.112015-11-08 17_03_19-GNS3 IOU VM [En fonction] - Oracle VM VirtualBox
  • Stop the VM
  • Go the virtualbox settings and change the network adapter from nat back to host only

2015-11-08 17_04_11-GNS3 IOU VM - Paramètres

2015-11-08 17_04_18-Oracle VM VirtualBox - Gestionnaire de machines

Files needed

Files for Cisco IOU and GNS3

Files for Cisco vIOS on GNS3

  • GNS3 latest version
  • vIOS L2 image

Files for Unified Networking Lab

  • UNL file
  • VMware Workstation or VMware player

Useful links to build a switching lab

How To Connect Cisco IOU and Emulate Cisco Switch in GNS3 1.1

How to Emulate a Cisco Switch

Layer 2 Switch With Full IOS in GNS3

Connection Problem With The Latest vIOS Image in GNS3

Unified Networking Lab OVA file

Unified Networking Lab: Documentation

http://www.smartpctricks.com/2014/11/connect-cisco-iou-to-gns3-1-1.html

Comments

Post a Comment

Popular posts from this blog

The Thing With CUCM Device Packs

Image
To add a new phone on CUCM, whether it is a Cisco phone or one of the free softphones on the Internet, you go to Device –> phone. Sometimes the phone you want to add does not exist in the drop box, because the device model is new or the CUCM version is a bit old. What you can do here is to download a Device Pack of the new phone and install it. A Device Pack is a set of firmwares contained in a single file. Generally, it has the extension “sgn”. A Device Pack for phone X not only contains a load for it, but also loads for many other phone models. This is important to know because, once you install a Device Pack in CUCM, your existing phones by default will install the new version of their respective loads. I encountered a case where, after installing a Device Pack, some phones no longer worked. So I had to note down the “Active Load” and put it in the Device Defaults page. CUCM Device Pack download To download a Device Pack, you need to have a valid Cis...
Read more

En Bloc Dialing vs Digit-By-Digit Dialing

Image
Digit Signaling, aka Digit Addressing, is the method by which digits are sent from a dialing endpoint (e.g. phone) to a CUCM server, or by a voice gateway or trunk. There are three known digit signaling methods: En Bloc dialing SIP Dial Rules Digit-by-digit dialing 1. En Bloc digit dialing In the En Bloc digit signaling method, digits are sent as a whole block. Think of it like a brick that you send to UCM. This is the digit addressing method used on Type A Cisco phones, whether the endpoint signaling protocol is SIP or SCCP. En Bloc dialing is the default method used with the famous gateway protocols -MGCP, H323 and SIP- and also on H323 trunks and SIP trunks. Besides, the resulting pattern of a Translation Pattern operation is sent as En bloc to the call control system. 2. SIP Dial Rules It is important to know that all SIP phones support SIP dial rules, whether they are Type A or Type B. SIP dial rules are created on CUCM and downloaded by...
Read more

Call Forward And Call Hunt on CUCM

Image
Call forwarding is one of the features of the call coverage in Cisco CUCM. Call Hunting is when CUCM distributes a call on more than one Directory Number (DN), whether consecutively or simultaneously, depending on the algorithm. Hunt Pilot A Hunt Pilot is the entry point for the whole call hunting process. It is hit by a Call. The Hunt Pilot number is a dialable entity and has many similarities with Route Patterns : We can configure Route Filters with Hunt Pilots, Hunt Pilots can Provide Outside Dial Tone , We can set Hunt Pilots with the Urgent Priority flag, They can route or block calls, They can apply Calling and Called Party Transformations. Hunt Lists After hitting the Hunt Pilot, the call is presented by CUCM to the Hunt List. Each Hunt List contains one or more ordered Line Groups. A Hunt List can be pointed by one or more Hunt Pilots. Line Groups Each Line Group contains one or more member (we’ll refer to them as Hunt members, hunt parties or Line Group members). A Line Grou...
Read more