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In this tutorial, you will learn how to build a Cisco switching lab … even though GNS3 cannot emulate a Cisco switch. I will show you how to use an NM-16ESW network module in a 3640 router to emulate a switching environment.

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If you have used GNS3 for any amount of time at all, you have encountered this situation. It’s late and you have been working on your lastest lab for hours. You decide to save your work. Logically, you go to File > Save. Unfortunately, the topology is saved but the router configs are gone.

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Do you get annoyed by Operating systems asking you if you are sure you want to perform an action 10 times before it will actually do what you want?

If so, you probably also get annoyed when your router gives you the old “Destination filename [startup-config]?” after you issue the “copy run start” command. Using the ‘file prompt quiet’ command will keep your router quiet.

Not only does this command stop annoyances, it is also the command you need to use if need to use file operations (copy, write, etc) with a kron job. I ran into a situation where a router configuration needed to be automatically backed up in two locations. I used the ‘archive‘ configuration to backup to an scp server and a kron job to backup to an ftp server. Without the ‘file prompt quiet’ command, the kron job fails.

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At different times, I have thought about creating training videos for Cisco certifications. After giving the idea a considerable amount of thought, I decided I don’t have enough time. So … I searched the net to find a company offering video training similar to my video tutorials.

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One of the major hurdles many people face with GNS3/Dynagen/Dynamips is that the emulators do not come with the Cisco Images to actually build a lab. It seems like once a week, I get an email with a request for an IOS Image, Pix Image, Pix Serial Numbers or Pix Activation codes. Just so I make myself clear, I will not give this information to you. Period. However…

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Have you ever wanted to keep notes inside a router instead of an external location? For a few years now, I have thought it would be great is Cisco would include a minimal text editor within the IOS code. It would be nice to have a notes inside the router regarding the last change that was made or other various notes.

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In this tutorial, you will learn how to build a small frame-relay lab. I will walk you through adding the routers, the frame switch, configuring the PVCs on the switch, and configuring the routers for basic point-to-point connectivity.

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In Part 2 of the GRE/IPSec tutorial series, you will learn how to encrypt the GRE tunnels you built in Part 1. Although I only show you how to create a hub and spoke topology, it is also possible to create a fully meshed topology or even a partial mesh. I highly recommend creating GRE tunnels from the branch to every datacenter in your organization.

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I first discovered GRE with IPSec about 4 years ago when a customer needed to transmit IPX and multicast traffic over his VPN. Since then, I have primarly used GRE/IPSEC tunnels for transmitting internal routing protocols over the internet.  RIP, EIGRP or OSPF can be used over a GRE tunnel just as though it were a point to point circuit. It is also very useful for multicast music on hold.

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In Part 1 of the Internet lab tutorial, we created a virtual "internet" using gns3. We built the infrastructure and configured a router to represent "The Internet" (ISP). This time, you will add switches and configure the internet routers at each customer site. Other tutorials will follow that use these two tutorials as a foundation.

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