Bit Indexed Explicit Replication For Layer 2 Networking

• US 20150078380A1
• Filed: 11/07/2014
• Published: 03/19/2015
• Est. Priority Date: 09/17/2013
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wijnands, Ijsbrand, Shepherd, Gregory J., Nainar, Nagendra Kumar
• Granted Patent: US 10,218,524 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's
• CPC Class Codes: H04L 45/74 Address processing for routing

Abstract

Various systems and methods for performing bit indexed explicit replication (BIER). For example, one method involves receiving a link layer protocol frame at a network device. The link layer protocol frame includes a MAC address that identifies the link layer protocol frame as a being a multicast frame. The method then involves selecting a subset of ports included on the network device and forwarding the link layer protocol frame to only the selected subset of ports.

Claims

1. A method comprising:

receiving a link layer protocol frame at a network device, wherein

the frame comprises a multicast media access control (MAC) address,

the network device comprises a plurality of ports;

selecting a first subset of ports of the plurality of ports; and

forwarding a copy of the frame to only those ports included in the first subset of ports.

2. The method of claim 1, wherein

the selecting is based on a multicast forwarding entry in the frame.

3. The method of claim 2, wherein

the multicast forwarding entry comprises a plurality of elements, and

each element of the plurality of elements corresponds to a respective host.

4. The method of claim 1, further comprising:

determining whether the frame comprises the multicast forwarding entry, wherein

the determining comprises accessing an Ethertype field in the frame.

5. The method of claim 1, further comprising:

receiving an address announcement from a host, wherein

the address announcement includes information identifying a bit position assigned to the host.

6. The method of claim 1, further comprising:

updating a bit forwarding table.

7. The method of claim 2, further comprising:

modifying the forwarding entry.

8. The method of claim 1, further comprising:

adding an Ethertype value to the frame, wherein

the Ethertype value indicates that the frame comprises a multicast forwarding entry; and

adding the multicast forwarding entry to the frame.

9. The method of claim 1, wherein

the link layer protocol frame is an Ethernet frame.

10. A network device comprising:

a memory storing forwarding information;

one or more ports configured to receive a link layer protocol frame, wherein the frame comprises a multicast media access control (MAC) address; and

a processor configured to

select a first subset of ports of the plurality of ports, and

forward a copy of the frame to only those ports included in the first subset of ports.

11. The network device of claim 10, wherein

selecting the first subset of ports is based on a multicast forwarding entry in the frame,

the multicast forwarding entry comprises a plurality of elements, and

each element of the plurality of elements corresponds to a respective host.

12. The network device of claim 10, wherein the processor is further configured to:

determine whether the frame comprises the multicast forwarding entry, wherein

determining whether the frame comprises the multicast forwarding entry comprises accessing an Ethertype field in the frame.

13. The network device of claim 10, wherein the processor is further configured to:

receive an address announcement from a host, wherein

the address announcement includes information identifying a bit position assigned to the host.

14. The network device of claim 13, wherein the processor is further configured to:

update a bit forwarding table in response to receiving the address announcement.

15. The network device of claim 10, wherein the processor is further configured to:

modify the forwarding entry.

16. A system comprising:

storage means for storing forwarding information;

network interface means for receiving a link layer protocol frame, wherein

the frame comprises a multicast media access control (MAC) address, and

the network interface means comprises a plurality of ports; and

processing means for

selecting a first subset of ports of the plurality of ports, and

forwarding a copy of the frame to only those ports included in the first subset of ports.

17. The system of claim 16, wherein

selecting the first subset of ports is based on a multicast forwarding entry in the frame,

the multicast forwarding entry comprises a plurality of elements, and

each element of the plurality of elements corresponds to a respective host.

18. The system of claim 16, wherein the processing means is further configured to:

determine whether the frame comprises the multicast forwarding entry, wherein

determining whether the frame comprises the multicast forwarding entry comprises accessing an Ethertype field in the frame.

19. The system of claim 16, wherein the processing means is further configured to:

receive an address announcement from a host, wherein

the address announcement includes information identifying a bit position assigned to the host.

20. The system of claim 16, wherein the processing means is further configured to:

update a bit forwarding table in response to receiving the address announcement.