What is so special about OTV?

[ranjipremandrewp]

What is so special about OTV? Why cant we just simply extend vlans across DCs using an L2 link between them using a service provider?

[Philip D'Ath]

I do that for the majority of my customers.

But lets say you have 3, 4 or a dozen data centres.  And lets say those data centres have 1000 physical servers.

L2 links just wouldn't scale.  Introducing OTV.  Or A-VPLS or even VPLS, EoMPLS, AToM, Multi-chasis Etherchannel, etc ....  Depends which religious camp you belong to.

[jeestrad]

OTV allows for a more easy-to-deploy aproach on L2 Tunnels, whereas other Technologies like MPLS, VPLS, might require a dedicated circuit between sites, OTV only needs IP reachability between sites. As Philip commented, one other advantage is the scalability to add more sites

-Enrique

[InayathUlla Sharieff]

Every feature carry its advantage. using L2 link I think you are taking about q in q tunneling old method. But if you read the OTV you would get to know the cool feature of what it does and what benifits you can get over it.

Please find link below which gives you the explanation on benifits of OTV compare to other similar feature:-

http://blog.ine.com/2010/02/15/what-is-overlay-transport-virtualization/

HTH

[ccie nithin]

You can achieve L2 extension between different DC using some other methods( like l2 tunnel,extending vlans on dedicated links,MPLS,VPLS etc).

OTV has some unique features,

=> simple configuration.

->redundancy 

=> extending L2 across multiple sites

=> no STP dependency.

=> No ARP flooding.