How to build a Layer 2 transit network

[PIKEYMIKEY]

What are the basic requirements and commands needed to build a layer 2 transit network between two sites?

Both sites will be connected by a 3rd party router which I do not have access to.

I will have access to the 3850's on each site.

[Seb Rupik]

Hi there,

What you are after is a Layer2 overlay which can be run between two endpoints separated by an IP network.

Good choices from the DCI environment would be OTV or VXLAN or perhaps simpler options such as L2TP.

What ever you choose, you will not be able to achieve it with 3850's, you are going to need a router of some description. 

Do you have routers at both sites which you manage? What models?

EDIT: If you had some spare server infrastructure at both sites you could feasibly spin up two linux hosts and establish a IPsec/ VXLAN connection between them and have the 3850 route traffic towards the local linux host which is destined for the other remote site.

cheers,

Seb.

[Giuseppe Larosa]

Hello PikeyMikey,

if there is a router in the middle and your devices are switch C3850  I don't see any  easy option to do this.

If you had two routers on your sites and you were looking for ways to transport L2 traffic over an IP routed network you could use L2TPv3 may be Vlan based.

L2TPv3 is supported on C7600 with ES linecards on access see the following thread

https://community.cisco.com/t5/metro/using-l2tp-xconnect-on-7600-es20/td-p/1463853

You should check on feature navigator if L3TPV3 is supported on switch 3850.

I don't think so.

Edit:

I have checked on feature navigator in IOS XE ethernet over L2TP3 requires an ISR router like 4331.

see

https://cfn.cloudapps.cisco.com/ITDIT/CFN/jsp/index.jsp

use research features and filter results using keyword L2TPv3

Hope to help

Giuseppe