The guys at GNS3.net have done it again! They just released version .04 of their incredible network emulation software. There are lots of new features including Pemu integration, c1700 and WICs Support and Project feature (you can keep router configs, nvram …).
In a previous tutorial, you learned how to install Call Manager 4.x in vmware. Installing CUCM 6.x in VMWare is much easier. Cisco did a great job with CUCM 6.x in terms of allowing you to install the software in a virtual machine without needing to hack the system.
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.
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.
