Underlay overlay correlation for visibility and debugging

A method comprising:

• receiving, by a first network device in a network, a flow having source information corresponding to a first client device and destination information corresponding to a second client device;
• creating, by the first network device, a tag for the flow based upon the source information and the destination information, wherein creating the tag comprises creating a hash based upon the source information and the destination information, wherein the source information comprises an internet protocol address of the first client device and a source port identifier of a port on the first network device that the first client device is connected and wherein the destination information comprises an internet protocol address of the second client device and a source port identifier of a port on a second network device that the second client device is connected;
• encapsulating, by the first network device, a packet corresponding to the flow, wherein encapsulating the packet comprises encapsulating the packet with encapsulation information including the created tag;
• exporting, by each of the plurality of intermediate network devices to a network management device, a flow entry corresponding to a routed encapsulated packet, the flow entry including the tag;
• and
• correlating, by the network management device, the flow from the first network device through the plurality of intermediate network devices based upon the tag wherein correlating the flow further comprises checking a source port identified by the tag to see that it matches a flow from one of the following:
• the first network device and the second network device.

An apparatus comprising:

• a memory storage;
• and
• a processing unit coupled to the memory storage, wherein the processing unit is operative to:
• receive a flow having source information corresponding to a first client device and destination information corresponding to a second client device;
• create a tag for the flow based upon the source information and the destination information, wherein the processing unit being operative to create the tag comprises the processing unit being operative to create a hash based upon the source information and the destination information wherein the source information comprises a source address corresponding to the first client device and a source port identifier corresponding to the first client device and wherein the destination information comprises a destination address corresponding to the second client device and a destination port identifier corresponding to the second client device;
• encapsulate a packet corresponding to the flow, wherein encapsulating the packet comprises encapsulating the packet with encapsulation information including the created tag;
• export a flow entry corresponding to a routed encapsulated packet, the flow entry including the tag;
• and
• correlate the flow from the first network device through the plurality of intermediate network devices based upon the tag wherein the processing unit being operative to correlate the flow comprises the processing unit being operative to check a source port identified by the tag to see that it matches a flow from one of the following:
• the first network device and the second network device.