MULTICAST MULTIPATHING IN AN IP OVERLAY NETWORK

• US 20150127701A1
• Filed: 10/07/2014
• Published: 05/07/2015
• Est. Priority Date: 11/05/2013
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Chu, Kit Chiu, Edsall, Thomas J., Yadav, Navindra, Matus, Francisco M., Doddapaneni, Krishna, Sinha, Satyam, Merchant, Sameer
• Granted Patent: US 9,654,385 B2
• Time in Patent Office: Days
• US Class Current: 709/201
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 12/4645 Details on frame tagging routing of packets H04L45/00; support for virtual LAN H04L49/354
• CPC Class Codes: H04L 2212/00 Encapsulation of packets
• CPC Class Codes: H04L 41/0654 using network fault recovery ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/0852 Delays
• CPC Class Codes: H04L 43/0894 Packet rate
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/021 Ensuring consistency of routing table updates, e.g. by using epoch numbers
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 45/245 Link aggregation, e.g. trunking
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/48 Routing tree calculation
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]
• CPC Class Codes: H04L 45/64 using an overlay routing layer
• CPC Class Codes: H04L 45/74 : Address processing for routing
• CPC Class Codes: H04L 45/745 : Address table lookup; Address filtering
• CPC Class Codes: H04L 45/7453 : using hashing
• CPC Class Codes: H04L 47/125 : by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 49/70 : Virtual switches
• CPC Class Codes: H04L 51/214 : using selective forwarding
• CPC Class Codes: H04L 61/2503 : Translation of Internet protocol [IP] addresses
• CPC Class Codes: H04L 61/2592 : using tunnelling or encapsulation
• CPC Class Codes: H04L 67/10 : in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 69/22 : Parsing or analysis of headers

Abstract

The subject technology addresses the need in the art for improving utilization of network bandwidth in a multicast network environment. More specifically, the disclosed technology addresses the need in the art for extending multipathing to tenant multicast traffic in an IP overlay network, which enables the network to fully utilize available bandwidth for multicast traffic. In some examples, nodes in the overlay network may be connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network.

Claims

1. A system, comprising:

at least one processor;

a network interface; and

memory including instructions that, when executed by the at least one processor, cause the system to;

receive, over the network interface, a multicast packet for distributing to a set of receivers in an overlay network;

perform a hash operation on at least a portion of the multicast packet to determine a hash key;

select a forwarding tag (FTAG) value based at least on the hash key;

concatenate an overlay multicast group value with the FTAG value to provide a destination address;

encapsulate the multicast packet with the concatenated overlay multicast group value and the FTAG value; and

forward the encapsulated multicast packet to a network element located at a next-hop in the overlay network.

2. The system of claim 1, wherein the multicast packet is received by a virtual extensible local area network (VXLAN) tunnel end point (VTEP) in the overlay network.

3. The system of claim 1, wherein the hash operation is performed on at least one of an IP destination address or an IP source address in an IP header of the multicast packet, information in an layer 2 (L2) header, or information in the multicast packet indicating a UDP port number or a TCP port number.

4. The system of claim 1, wherein the FTAG value is associated with a multicast distribution tree in the overlay network, the multicast distribution tree being selected from a plurality of different multicast distribution trees in the overlay network.

5. The system of claim 1, wherein the overlay multicast group value comprises an overlay multicast group address.

6. The system of claim 5, wherein the FTAG value comprises a lower four bits of a header field including the concatenated overlay multicast group value and the FTAG value.

7. The system of claim 1, wherein to encapsulate the multicast packet further causes the at least one processor to:

append a VXLAN header field to an Ethernet frame, the Ethernet frame including the multicast packet in an Ethernet payload portion of the Ethernet frame; and

update an outer IP destination address field in the VXLAN header with the concatenated overlay multicast group value and the FTAG value.

8. The system of claim 1, wherein the network element located at the next-hop in the overlay network comprises a spine switch.

9. The system of claim 8, wherein the spine switch comprises a root node in a multicast distribution tree associated with the FTAG value.

10. A computer-implemented method, comprising:

receiving, over the network interface, a multicast packet for distributing to a set of receivers in an overlay network;

performing a hash operation on at least a portion of the multicast packet to determine a hash key;

selecting a forwarding tag (FTAG) value based at least on the hash key;

concatenating an overlay multicast group value with the FTAG value to provide a destination address;

encapsulating the multicast packet with the concatenated overlay multicast group value and the FTAG value; and

forwarding the encapsulated multicast packet to a network element located at a next-hop in the overlay network.

11. The computer-implemented method of claim 10, wherein the multicast packet is received by a virtual extensible local area network (VXLAN) tunnel end point (VTEP) in the overlay network.

12. The computer-implemented method of claim 10, wherein the hash operation is performed on at least one of an IP destination address or an IP source address in an IP header of the multicast packet, information included in a layer 2 (L2) header, or information in the multicast packet indicating a UDP port number or a TCP port number.

13. The computer-implemented method of claim 10, wherein the FTAG value is associated with a multicast distribution tree in the overlay network, the multicast distribution tree being selected from a plurality of different multicast distribution trees in the overlay network.

14. The computer-implemented method of claim 10, wherein the overlay multicast group value comprises an overlay multicast group address.

15. The computer-implemented method of claim 14, wherein the FTAG value comprises a lower four bits of a header field including the concatenated overlay multicast group value and the FTAG value.

16. The computer-implemented method of claim 10, wherein to encapsulate the multicast packet further comprises:

append a VXLAN header field to an Ethernet frame, the Ethernet frame including the multicast packet in an Ethernet payload portion of the Ethernet frame; and

update an outer IP destination address field in the VXLAN header with the concatenated overlay multicast group value and the FTAG value.

17. The computer-implemented method of claim 10, wherein the network element located at the next-hop in the overlay network comprises a spine switch.

18. The computer-implemented method of claim 17, wherein the spine switch comprises a root node in a multicast distribution tree associated with the FTAG value.

19. A non-transitory computer-readable medium including instructions stored therein that, when executed by at least one computing device, cause the at least one computing device to:

receive, over the network interface, a multicast packet for distributing to a set of receivers in an overlay network;

perform a hash operation on at least a portion of the multicast packet to determine a hash key;

select a forwarding tag (FTAG) value based at least on the hash key;

concatenate an overlay multicast group value with the FTAG value to provide a destination address;

encapsulate the multicast packet with the concatenated overlay multicast group value and the FTAG value; and

forward the encapsulated multicast packet to a network element located at a next-hop in the overlay network.

20. The non-transitory computer-readable medium of claim 19, wherein the FTAG value is associated with a multicast distribution tree in the overlay network, the multicast distribution tree being selected from a plurality of different multicast distribution trees in the overlay network, the overlay multicast group value comprises an overlay multicast group address, and the FTAG value comprises a lower four bits of a header field including the concatenated overlay multicast group value and the FTAG value.