Why should I use MPLS L3 VPN over DMVPN ??

[laxmicisco]

Why should I use MPLS L3 VPN over DMVPN ??

[Georg Pauwen]

Hello,

have a look at the link below:

https://ipwithease.com/dmvpn-vs-mpls/

[balaji.bandi]

Not necessarily only required to use MPLS, You can use DMVPN over the Internet.

either case Hub has some reservations always to meet the requirement.

[Georg Pauwen]

Hello,

you would use this mainly to overcome the issue of overlapping IP address spaces.

Check the link below:

Chapter: Configuring MPLS over DMVPN

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sec_conn_dmvpn/configuration/xe-16-10/sec-conn-dmvpn-xe-16-10-book/sec-conn-dmvpn-xe-16-10-book_chapter_010000.html

[hashemouaida]

MPLS is a technology that has several advantages over other protocols. It can be used with different L3 routing technologies such as IPv4, IPv6 and beyond. It uses "Labels" instead of IPv4, IPv6 addresses to forward packets.

MPLS is slightly faster in older routers however in modern routers its not a significant difference.  MPLS is very flexible and can support many technologies such as Quality of Service, multicast, VPN's, etc.

However the biggest advantage is MPLS decreases forwarding overhead on core routers. It does it this by making the core more efficient and reducing CPU and RAM power. 

[Joseph W. Doherty]

"Why should I use MPLS L3 VPN over DMVPN ??"

Because MPLS WAN vendors will tell you it's "better". 

BTW, assume you mean DMVPN over Internet, right?

Biggest advantages of MPLS, doesn't need to "consume" portion of original MTU of packets.  Often MPLS can also provide egress (from "cloud") QoS support typically not available from ISPs (technically they might easily support it, but, again, they generally won't).

Biggest advantage of DMVPN would be, generally, much lower cost than MPLS L3 VPN.  Also, Internet is much easier to obtain worldwide than MPLS.  (Later versions of DMVPN which can support Adaptive QoS can mitigate, somewhat, the lack of "cloud" egress QoS.)

There are other pros and cons of the two technologies, as noted in Georg's reference (although I wouldn't fully agree with all as described), but the above, might be the most "important".

[Giuseppe Larosa]

Hello @laxmicisco ,

it is not clear if you would like to compare the two technologies or you are referring to a specific case where both are used.

For a comparison we can say the following:

MPLS L3 VPN is more scalable in terms of number of sites and throughput per site.

MPLS L3 VPN uses a peer model where each device just exchanges routes with the directly attached PE node.

The resulting connectivity between sites and the scalability is the result of the MP BGP control plane of the service provider.

This is a property of the protocol and there is no need for a single device to host all the information, also the RR servers of service providers can be specialized for MPLS L3 VPN service and can serve a subset of customers.

Customer routers do not need to encrypt traffic as it is not sent on the publice internet ( in some cases this is done for additional security reasons).

This allows to save money on the routers but generally an MPLS L3 VPN access link costs more then an internet link.

MPLS provide consistent end to end QoS and for example for VOIP traffic or video traffic can be better.

DMVPN allows to leverage over internet connections but the HUB router(s) and the spoke routers require HW assisted encryption/decryption . The HUB routers provide an upper limit to the number of spoke sites that can be served.

For serving thousands of spokes you would need very powerful hub routers and eventually a load balancer in front of them or to use multiple DMVPN clouds and to have hubs interconnected.

DMVPN is well suited for branch offices with no critical applications and low to moderate use of bandwidth when accessing central services.

DMVPN can be much cheaper in this scenario but require more powerful routers and additional security licenses.

Last but not least DMVPN is Cisco proprietary so it would lead to use all Cisco routers in all branch and HQ.

GET VPN is the multivendor standard near DMVPN features.

Hope to help

Giuseppe