Multi DataCenter Interconnect using OpenContrail

In typical Enterprise Data Center deployments, the data center would span across multiple sites and there would be a need to have workloads across these sites. This would boil down to extending virtual networks to these multiple sites and ability to launch workloads on any site and be able to communicate between these workloads seamlessly as if they are in the same cluster.

In OpenContrail, this is made possible by federating the controllers in the different sites of a Multi-site DC without the need of a physical gateway. The control nodes in each site are peered with other sites using BGP. With this it is possible to stretch both L2 and L3 networks across multiple DCs.

The physical topology in this case is as shown below:

physical_topology_opencontrail_controller_federation_blogpost

The two DCs in different locations are having two different AS numbers and their control nodes are federated using BGP. The virtual networks can span across these two DCs. Also the network policies and security groups can also work seamlessly across these two DCs.

The logical view of the system is shown below:

logical_view_opencontrail_controller_federation_blogpost

Logically, the virtual machines spawned in another DC in the same VN can talk to each other like VMs in the same DC. They don’t see any difference.

A demo video on how controller can be federated in OpenContrail is available here:

With this, we have shown that using controller federation in OpenContrail; we can seamlessly stretch virtual networks ( both Layer 3 and Layer 2), network policies and security groups across multiple remote data center locations.