Efficient multicast packet forwarding in a distributed tunnel fabric

A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method, the method comprising:

• maintaining, by a first switch, a first tunnel with a second switch in an overlay tunnel fabric that includes the first and second switches, wherein encapsulation of a packet sent via the overlay tunnel fabric is initiated and terminated within the overlay tunnel fabric;
• maintaining, by the first switch, a second tunnel with a third switch in an external network that excludes the first and second switches;
• distinguishing the first and second tunnels as intra-fabric and inter-fabric tunnels, respectively, of the overlay tunnel fabric;
• and
• in response to receiving a multicast control packet via the first tunnel:
• identifying the second tunnel as the inter-fabric tunnel;
• and
• forwarding the multicast control packet via the second tunnel, wherein a respective multicast control packet received from the first tunnel is precluded from being forwarded on intra-fabric tunnels of the overlay tunnel fabric.

A computer system, comprising:

• a processor;
• a memory device;
• a tunnel logic block to:
• maintain a first tunnel with a second computer system in an overlay tunnel fabric that includes the computer system and the second computer system, wherein encapsulation of a packet sent via the overlay tunnel fabric is initiated and terminated within the overlay tunnel fabric;
• and
• maintain a second tunnel with a third computer system in an external network that excludes the computer system and the second computer system;
• a classifier logic block to distinguish the first and second tunnels as intra-fabric and inter-fabric tunnels, respectively, of the overlay tunnel fabric;
• a forwarding logic block to receive a multicast control packet via the first tunnel;
• and
• a control logic block to:
• identify the second tunnel as the inter-fabric tunnel;
• and
• forward the multicast control packet via the second tunnel using the forwarding logic block, wherein a respective multicast control packet received from the first tunnel is precluded from being forwarded on intra-fabric tunnels of the overlay tunnel fabric.