Layer 2 WAN Connectivity

[Bab L]

Hi all.

This is something new for me and I'd appreciate any help.

We have currently a Layer 2 WAN connection through a 3rd party provider. They use 3400 switches to connect two different sites. One is our DC and the other one is the client. In our DC we have two switches in stack mode 3750Gs. The client has two Dell switches in stack mode as well - Layer 3 switches. We need to configure communications of both sites via the link to perform replication. We do not want VLANs to go through the WAN. What is the best way of configuring our switches? We cannot configure the 3rd party switches.

Thanks for your help.

[SANTHOSHKUMAR SARAVANAN · Accepted solution]

Hi ,

 If you have got VPLS services from your service provider , You can perform replication between two location , without any addition VLAN creation on your switches . (Same VLAN can be spanned between both datacenter) .

http://www.cisco.com/c/en/us/products/ios-nx-os-software/virtual-private-lan-services-vpls/index.html

If it DWDM link , You can ask your service provider to create new VLAN for your replication , same can extended to your both end switches . 

https://www.cisco.com/en/US/docs/storage/san_switches/mds9000/sw/rel_3_x/configuration/guides/fm_3_4_x/dwdm.pdf

HTH

Sandy

[Bab L]

Thanks for the reply.

So in your first option, can the two swtiches on both ends belong in the same subnet?

How is routing going to work?

[SANTHOSHKUMAR SARAVANAN · Accepted solution]

Yes , it will work if you have taken VPLS services . If they want to communicate within same LAN segment , gateway is not required .

If they want to communicate between network segment or other network segment , gateway must be configured . Gateway should be on one data center .

Among your two data center, one datacenter must be the gateway  for these servers/end host

 Normally replication happens between same network subnet , not between network segment .

HTH

Sandy

[Bab L]

So, if the servers belong in the same subnet they can communicate via the link with no further configuration on the ISP switches? I just need to plug in the switches on their interface and packets will find their way?

[SANTHOSHKUMAR SARAVANAN]

Yes , it should work if you have configured same VLAN on both side , including your service provider switches .

Check with your service Provider on VLAN extension 

HTH
sandy 

[Bab L]

I know that its possible to use same VLAN via the ISP switches but this will require a variation of contract which we do not want to do.

The ISP switches are setup with two different VLANs on both sides. If I plug in our switches and the clients switches using a new vlan number, will they communicate via the link?

[Bab L]

-