Graphical Network Simulator - GNS3. Connecting GNS3 to Real Networks. Last updated on November 22nd, 2012 One of the interesting things about GNS3 is that you can connect your topology to the real world. For some of your CCNA and CCNP studies you may need to run an actual Web browser or Cisco’s Security Device Manager (SDM) among others. Just connect your topology to your real PC. You could even connect to virtual machines running on your computer inside VMware or Virtual PC.
I’ve even set up two copies of Windows XP Professional running inside VMware virtual machines. Then, I ran Cisco soft IP Phones that could talk to each other. Drag a Cloud into your workspace. For Windows users, click on the box directly beneath Generic Ethernet NIO, and choose the network adapter you wish to use. You may use your regular network adapter, but I usually create an MS Loopback adapter to connect to. Now start your router and assign an IP address to the interface that is connected to the Cloud. Connecting a host PC to your devices in GNS3 (Part 1) | Intense School. Connecting a host PC to your devices in GNS3 (Part 1) This article and the next one following it will be precursors to a series we will be starting on the Cisco Configuration Professional (CCP) which will be especially helpful to those studying for their CCNA Security certification exam.
For those who want a more realistic and flexible configuration environment while preparing for their certification exams or even lab environments in general, GNS3 is a good option which is also free (except, of course, the Cisco IOS that will be used). In this article, we will be considering how to connect GNS3 devices (e.g. routers, ASAs, etc.) to a host system such as the one GNS3 is installed on or even virtual machines. I have used this method during my CCIE prep to build full labs including Intrusion Prevention Systems and Windows server operating systems. GNS3 Environment I’d be using GNS3 version 0.8.3.1 and although there is a newer version out now, the basics will be the same.
GNS3 Setup Summary. Video tutorials. Introduction to GNS3. GNS3 is a Graphical Network Simulator that allows emulation of complex networks. You may be familiar with VMWare, VirtualBox or Virtual PC that are used to emulate various operating systems in a virtual environment. These programs allow you to run operating systems such as Windows XP Professional or Ubuntu Linux in a virtual environment on your computer. GNS3 allows the same type of emulation using Cisco Internetwork Operating Systems. It allows you to run a Cisco IOS in a virtual environment on your computer. Dynamips is the core program that allows IOS emulation. GNS3 also supports other emulation programs, namely Qemu, Pemu and VirtualBox.
GNS3 allows the emulation of Cisco IOSs on your Windows, Linux and Mac OS X based computer. There are a number of router simulators on the market, but they are limited to the commands that the developer chooses to include. In addition, GNS3 is an open source, free program for you to use. Switching simulation in GNS3. Frame Relay and ATM devices An integrated Frame Relay switch is provided by GNS3. It is actually part of Dynamips. Just drag the Frame Relay switch from Nodes Types into the workspace. Right-click on the Frame Relay switch and choose Configure. Now you may assign your DLCIs at the source and destination – creating a frame relay map between the two. In our example below, local DLCI 102 on port 1 is mapped to DLCI 201 on port 2. Also note that the simple Frame-Relay switch only understant ANSI LMIs, don’t forget to set the LMI type on your Router’s serial interfaces (default type is CISCO) using the following command: frame-relay lmi-type ansi If you want more control over Frame-Relay, please configure an IOS instance to act as a Frame-Relay switch.
Ethernet Switch devices GNS3 with Dynamips help integrates an Ethernet switch that supports VLANs with 802.1q trunking. By default, there are 8 ports in VLAN 1 configured as access ports. Show mac switch_name clear mac switch_name EtherSwitch Cards. Adding hosts to your Topologies. There are four possible ways to add a computer to your topology. If you just need to check for connectivity using ping or traceroute, the best way is to use the Virtual PC Simulator. The second way is to use a Qemu or VirtualBox guest (Qemu and VirtualBox support are integrated into GNS3). Third way is adding another router but configure it to act like a PC. Finally, you may use your real PC as described in the Connecting GNS3 to real networks tutorial.
Using the Virtual PC Simulator (and the Symbol Library) The Virtual PC Simulator is a program that runs within Windows orLinux. Extract the archive to your PC, and then in Windows run vpcs.exe If you are running Linux, following these additional steps: right-click the vpcs (not vpcs.exe) and choose Properties. Now just click the VPCS icon on your desktop as it is best to open the Virtual PC Simulator before starting GNS3.
For help, just type ? Ip 192.168.1.1 192.168.1.254 24 ip 192.168.2.1 192.168.2.254 24 The program is very easy to use. PIX Firewall Emulation. GNS3 is also capable of emulating PIX firewalls. Once again, you’ll need to provide your own PIX image. If you want to run more than a restricted license, you’ll also need to have a valid serial number and activation keys. Installation Pemu, the program to emulate PIX OS, is already included in Windows all-in-one and standalone packages. For Linux, you have to manually download Pemu and install it in the exact same directory as Qemuwrapper.py. Note that Pemu is not supported on Mac OS X excepting if you manage to compile the sources.
Configuring Qemuwrapper and Cisco PIX image First, go to Preferences on the Edit menu in GNS3. On PIX tab, use the button next to Binary image to specify the location of your PIX operating system image. You may use the default Key and Serial number, if necessary. If you have a serial number and valid activation keys, you may move from a restricted license to an unrestricted license. Using Cisco PIX Click OK to return to the GNS3 main interface. Using terminal programs with GNS3. Last updated on July 2nd, 2014 By default, GNS3 uses Putty on Windows, xterm on Linux and Terminal on Mac OS X.
But if using Windows for instance, you may prefer to use TeraTerm or SecureCRT (used in CCIE labs). Just download the terminal program you prefer and install it on your computer. Inside GNS3, choose Preferences under the Edit menu. Choose General in the left pane, then terminal settings. To save you time, GNS3 comes with preconfigurated terminal commands. The current preconfigurated terminal commands are: Putty (Windows 64 bits)Putty (Windows 32 bits)Putty (Windows, included with GNS3)SecureCRT (Windows 64 bits)SecureCRT (Windows 32 bits)TeraTerm (Windows)Telnet (Windows)xterm (Linux/BSD)Putty (Linux/BSD)Gnome Terminal (Linux/BSD)KDE Konsole (Linux/BSD)Terminal (Mac OS X)iTerm (Mac OS X) Please note that since Windows Vista, the telnet client is not automatically installed as in previous versions of Windows.
Please contact us to add new preconfigured terminal commands in GNS3. Client-Server and Multi-Server Mode. The Dynamips hypervisor mode used by GNS3 uses a TCP/IP communications channel. This means that GNS3 may run on one machine, while the Dynamips emulator may run on a different machine. Choose IOS images and hypervisor on the Edit menu in GNS3. Under the Hypervisors tab, manually specify a hypervisor. Here we recorded a 2 new hypervisors which will listen respectively on port 7211 and 7212 on the “remote_host” machine. You can also specify the fully qualified path to the working directory where the hypervisors will store all of their generated files on the Dynamips host. Be sure to use the correct directory separation character for the platform. You must use a DNS name or an IP address in the Host text box.
Base UDP is the base port for UDP NIOs that Dynamips uses to make the connections between your nodes. NIO stands for Network I/O. Here is an output of the netstat command that shows you the connections between the nodes and the UDP port picked up by Dynamips. Creating the Simplest Topology. We describe how to build a more complex topology later, but for now, let’s just learn how to place one router on the desktop, start it, and console into it.
We will then learn how to find an idlepc value for the IOS we are using. This is a very important step. When an IOS is running, it will consume up to 100% of your CPU time. This will cause your computer to become very sluggish and will prevent building more complex topologies. However, if we use an idlepc value, we can reduce CPU usage dramatically. It puts the IOS into a sleep state when it is not in active use and wakes it up only when it is necessary. The GNS3 window is divided into four panes by default. The right-most pane will provide a topology summary that will be better understood when we built more complex topologies. The middle section contains two panes. Configuring a router Click on a router icon under Nodes Types corresponding to the IOS platform you are using.
Click on R1 and then the Slots tab. Apply an idlepc value. Packet Capture. Last updated on November 22nd, 2012 GNS3 can capture packets on virtual Ethernet or serial interfaces. It will write the captured output to a libpcap file that may be viewed using WireShark. WireShark may be downloaded on Suppose we want to capture packets passing through the Serial interface on R2 (s0/0). Right-click somewhere along the line representing the link between R1 and R2. The drop-down arrow will allow you to choose which interface to monitor (R1 s0/0 or R2 s0/0). Notice that we can also choose the encapsulation type for serial interfaces. Now let’s generate some traffic to test our capture. Let’s back up and talk about the preferences for capturing packets.
Also, note that you can see the ongoing captures in a window pane that you can activate in View menu-> Docks -> Captures. Screenshots. GNS3 has been developed in python and through PyQt the GUI part is made with the powerful Qt library , famous for its use in the KDE project. GNS3 uses the SVG technology (Scalable Vector Graphics) to provide high quality symbols for designing your network topologies.