2 vlans 1 subnet

[simplyme]

Hi all,

Long time reader, 1st time poster :)

I have a situation whereby I need to stretch vlans from one DC to another, that is the easy part and I have 18 of 20 vlans working. 

My issues is as follows.

I have a DC in location 1, this has an mpls network, etc behind it. I have a 3650, access ports configured (vlans 1-10 on ports 1-10, these are received from firewall) and vlans 20-30 on ports 20-30. I then trunk into my existing infrastructure and then dot1q tunnel back to my 2nd DC. Vlans are fed back to another 3650 and if I build SVI's to test, all works as it should apart from 2 vlans. 

Vlan 30 = native vlan for data network (10.10.10.0/24 as an example)

Vlan 10 = All firewall traffic for the network, also on 10.10.10.0/24

I have attached another 3650 and trunked vlans 1-10 on there and built SVI for vlan 10. 

The problem I have, as you can imagine, is Vlan30 gets all the ARP caches. I think this is due to vlan broadcast containment. 

My question is, how do I get vlan 10 to talk to vlan 10 in my new DC? 

Reading back I am not sure if this makes sense so I have added a diagram.

[Julio E. Moisa]

Hi

I think the solution could be using L2TPv3 to create a layer 2 tunnel.