When do you use dmvpn ?

[carl_townshend]

Hi all, what do most people generally use a dmvpn setup for? mpls backup? Or backup wan connections over the Internet?

[Reza Sharifi]

Here is good doc on DMVPN to look at:

http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6586/ps6635/ps6658/data_sheet_c78-468520.html

HTH

[rittam bhattacharya]

Hello Guys,

I am confused between multipoint GRE and DMVPN.

Suppose we have 2 spokes and 1 hub. now if I run the multipoint GRE without nhrp and run the dynamic protocol over mGRE tunnel then I can achieve the things what I need, 

So why should I use the glue of nhrp and why I need DMVPN ?

[Joseph W. Doherty]

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Posting

For just 3 nodes, you might just use GRE.

NHRP provides the capability that spoke IPs can be dynamic.

DMVPN provides encryption.

DMVPN rides over mGRE but if you don't need NHRP or encryption (or per hub to spoke QoS [or dynamic shaping]), don't see why you couldn't just use mGRE.

[rittam bhattacharya]

but can't we implement encryption over mGRE ?

I don't want to use nhrp, I hate it.

I want to achieve the thing without nhrp, and if we can (alongwith encryption), then why to use DMVPN ?

[Marwan ALshawi]

Hi Carl

Just to add to Reza post,

DMVPN is a very useful, flexible and scaleable tunneling technology where you can build a dmvpn tunneling cloud from simple hub and spoke topology to a multi tier complex hup and spokes topologies and it can be used with IPSec encryption for security and confidentiality but IPSec is optional but highly recommended

Ok ba k to the usage of this technology bellow are some examples where you can use it

- back up to the private WAN to be used over Internet for example

- if a customer has only Internet and with hub and many spokes and the spokes obtain their ip from the ISP not static then with dmvpn each spoke will register with the hub and the hub the will know about the spoke ip to be used as next hope for routing

-curry multi cast and routing traffic

- if a customer use it as main or back up method and they have VoIP dmvpn the best option here as with VoIP you will need direct RTP traffic between endpoints and this will be done by using the dmvpn spoke to spoke or branch to branch direct traffic

- if a customer have WAN network and they want to secure the ip communicatio. Over the WAN then DMVPN with IPSec encryption can be used and on top of it the routing can be run

Hope this help