DMVPN requires to deploy a certification authority server, using a single shared key is not secure enough.
We can say that DMVPN is more hard to deploy but it is far easier to mantain and should be a winning choice if number of remote sites increases over time.
Hub router configuration doesn't need to be changed when a new remote site has to be added this helps also on scalability.
DMVPN disadvantage: it is Cisco proprietary.
point-to-point GRE and IPsec is easier to setup but harder to mantain: adding a new remote site requires configuration on hub and new remote.
Also when doing changes there are some errors that can impact multiple remote sites: if for example in a crypto map block a non-existing ACL is invoked this is seen as a permit ip any any and causes that connectivity to all remote sites configured in following crypto map blocks is broken.
it is enough to delete an ACL to do this.
a possible advantage is that it is possible to accomodate a remote peer that has different authentication and encryption capabilities and non cisco devices.
A very fine answer indeed. There is one thing I wanted to point out, though - the DMVPN does not have to be implemented using IPsec. While of course every reasonable implementation of DMVPN uses IPsec for data confidentiality and integrity purposes, the IPsec itself is just an add-on on top of the real DMVPN provided by NHRP and multipoint GRE tunnels.
Regarding the proprietarity - actually, all protocols used in DMVPN are open and described in RFCs. A different thing, though, is that I haven't seen any other vendor implementing them.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.