DMVPN Part 1

I watched INE's YouTube video tonight for DMVPN part 1.  Seeing it broken down like that by Brian McGahan is actually quite interesting.  Didn't realize how easy it was.  Definitely learned a few things following along in my lab as he did it in the video.  Also not having the initial config was fun too because I had to figure out based on his output what he had configured for basic routing and configure my lab to match.  Made me feel something good that I could do that even if it was a super easy lab to configure for the initial setup.

What did I learn?  I learned that taking the initial config from Cisco's website is a great way to start since it is commented very well.  Great starting place to 1) understand and 2) get a basic config for the exam. 

I also learned that DMVPN is a lot more like frame relay than I suspected.  I had an inkling that it was and I can see it being used for OSPF DR and DROTHER usage as well as great tickets in the TS section.  And not only is it like frame relay with hub and spoke technology but also when thinking of mappings and how it works when looking at the output of show ip nhrp.  As Brian put it, think of the NMBA address as the DLCI in frame.

So, with no crypto it really isn't that hard to get the basics of but knowing Cisco there will be gotchas in it that  will cause someone and more than likely everyone to scream.

Now what is DMVPN?  It is basically a way to connect multiple sites using a hub location that all other sites connect to.  From here the mappings are made and stored for these remote locations so that the remote sites can find neighbors and then connect directly to each on an as needed basis.  Add crypto and you got yourself a completely meshed network that is secure and can be run over that pesky, ole internet.  Sounds hard but not really.  Issue, as Brian put it, was that it can be more complicated with more sites and needing redundancy.  Well, luckily v5 only requires one hub.  Yay for the little things in life.

Video part 1 covers the basic theory of DMVPN and the rudimentary CLI needed to get phases 1 completed.  Phase 1 is where all traffic flows through the hub site.  Nope.  Not very dynamic there.  Phases 2 and 3 are where the true power of the technology comes in and that is video part 2.  That will be tomorrow night for and I can't wait.

Was going to embed the video below but the Blogger site can't seem to find the video.  Instead here is the link

https://www.youtube.com/watch?v=CIWcYSClbio