Break Up Layer 2 Domains

[alfredobosca]

Now, I am analyzing a complex network that consists of hundreds of Switches between 2 interconnected buildings by Layer2. 

One month ago I suffered a Layer 2 loop that was propagated to both buildings. Due to I need to break up Layer 2 domains in order to isolate the effects of broadcast, flooding and Layer 2 loops.

In order to break layer 2 I need create Layer 3 interconnection but I have some old image servers that works with multicast traffic.

It seems with VXLAN this issue would be solved but I would lik to know more alternatives.

Thanks in advance!

[Julio E. Moisa]

Hi 

In order to separate the broadcast domain, you must use L3 devices, like routers or multilayer switches. Also you should have a tuned Spanning tree protocol in order to avoid Layer 2 loops. 

Other than that, you should be aligned to a network model, like 3 layered model or collapsed model. Please check this link:

http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Campus/campover.html

You always must consider to build a network in order to have:

- Scalability
- Performance
- High Availability
- Security

Among other characteristics. Your Point to Point between the building could be a Layer 3 instead Layer 2 and to use routing protocols. But is important to meet the requirements before to change it.

Hope it is useful

:-)

[alfredobosca]

Hello,

As spoke before we have a server with multicast traffic in Layer 2, this prevent a ease migration to Level3. In order to migrate L3 I would need solutions like VXLAN, Pluribus due to don't modify the frames and are encapsultaed in Packets.

Furthermore, we have STP but the L2 loops persists. I am not sure that all network has the same native vlan.

Best regards,