Policy based routing in extranet networks

A non-transitory computer-readable medium that stores a set of instructions which when executed perform a method comprising:

• receiving a first traffic at a first border node connected to a provider virtual network of a fabric network, wherein the fabric network comprises a plurality of virtual subnets interconnected with the provider virtual network by a plurality of intermediate nodes, and wherein the plurality of intermediate nodes provide Layer-3 underlay transport service to the first traffic;
• determining, by the first border node that the first traffic is associated with a first virtual subnet of the plurality of virtual subnets and is coming from the provider virtual network;
• determining, by the first border node in response to determining that the first traffic is coming from the provider virtual network, that the first virtual subnet associated with the first traffic is associated with a first subscriber virtual network of a plurality of subscriber virtual networks of the fabric network, wherein determining that the first virtual subnet is associated with the first subscriber virtual network comprises:
• performing, at the first border node, a first lookup in a table of subnets, wherein the first lookup is performed based on the first virtual subnet indicated by an IP address of the first traffic, wherein each of a plurality of border nodes of the fabric network comprises the table of subnets having a list of the plurality of virtual subnets associated with the plurality of subscriber virtual networks of the fabric network, and wherein the first border node does not maintain a complete list of addresses of hosts connected to the plurality of subscriber virtual networks of the fabric network, and
• determining, based on the first lookup, that the first virtual subnet is associated with the first subscriber virtual network and a locator address of an edge node connected to the first subscriber virtual network;
• changing, by the first border node in response to determining that the first virtual subnet is associated with the first subscriber virtual network, a second lookup address associated with the first traffic based on a first virtual routing and forwarding group of the first subscriber virtual network used by the edge node connected to the first subscriber virtual network for identifying a host of a plurality of hosts connected to the edge node wherein the first virtual routing and forwarding group comprises a complete list of address identifiers for the plurality of hosts connected to the edge node;
• and
• causing, by the first border node, the first traffic to directly hop to the edge node connected to of the first subscriber virtual network.

An apparatus comprising:

• a memory storage;
• and
• a processing unit coupled to the memory storage, wherein the processing unit is configured to:
• receive a first traffic at a first border node connected to a provider virtual network of a fabric network, wherein the fabric network comprises a plurality of virtual subnets interconnected with the provider virtual network by a plurality of intermediate nodes, wherein the plurality of intermediate nodes provide Layer-3 underlay transport service to the first traffic;
• determine that the first traffic is associated with a first virtual subnet of the plurality of virtual subnets and is coming from the provider virtual network of the fabric network;
• determine, in response to determining that the first traffic is coming from the provider virtual network, that the first virtual subnet associated with the first traffic is associated with a first subscriber virtual network of a plurality of subscriber virtual networks of the fabric network, wherein the processing unit being configured to determine that the first virtual subnet is associated with the first subscriber virtual network comprises the processing unit being configure to:
• perform a first lookup in a table of subnets, wherein the first lookup is performed based on the first virtual subnet indicated by an IP address of the first traffic, wherein each of a plurality of border nodes of the fabric network comprises the table of subnets that comprises a list of the plurality of virtual subnets associated with the plurality of subscriber virtual networks of the fabric network, and wherein the first border node does not maintain a complete list of addresses of hosts connected to the plurality of subscriber virtual networks of the fabric network, and
• determine, based on the first lookup, that the first virtual subnet is associated with the first subscriber virtual network and a locator address of an edge node connected to the first subscriber virtual network;
• change, in response to determining that the first virtual subnet is associated with the first subscriber virtual network, a second lookup address associated with the first traffic based on a first virtual routing and forwarding group of the first subscriber virtual network used by the edge node connected to the first subscriber virtual network for identifying a host of a plurality of hosts connected to the edge node, wherein the first virtual routing and forwarding group comprises a complete list of address identifiers for the plurality of of hosts connected to the edge node;
• and
• cause the first traffic to directly hop to the edge node connected to of the first subscriber virtual network.