Efficient multicast traffic forwarding in EVPN-based multi-homed networks

Patent metadata

Field	Value
Publication number	US-10164876-B2
Application number	US-201615374648-A
Country	US
Kind code	B2
Filing date	Dec 9, 2016
Priority date	Dec 9, 2016
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

Embodiments of the present disclosure relate to assisting forwarding of multicast traffic over Ethernet Virtual Private Network (EVPN) from a multicast source to a host multi-homed to multiple provider edge (PE) devices. Embodiments are based on the inclusion of an Ethernet Segment Identification (ESI) to EVPN type-6 routes advertised by PE devices which received a multicast Join message. Other PE devices receiving such routes are able to determine whether they belong to the ES identified by the ESI and to determine whether they are designated forwarders (DFs) for the host. Furthermore, PE devices which are the DFs are configured to re-originate the EVPN type-6 routes, i.e. re-send the advertisements, indicating themselves as DFs. This ensures that a remote PE device associated with the multicast source will also send multicast traffic to such DF PE devices, which, in turn, would allow the multicast traffic to successfully reach the host.

First claim

What is claimed is:

1. A computer-implemented method for assisting forwarding of multicast traffic over an Ethernet Virtual Private Network (EVPN) fabric from a multicast source to a host device multi-homed to a plurality of provider edge devices, the method comprising:
receiving, at a provider edge device not elected, out of said plurality of provider edge devices, to be a designated forwarder for said host device (non-designated forwarder provider edge device), an Internet Group Management Protocol (IGMP) join message;
sending, by the non-designated forwarder provider edge device, a first route advertisement message that includes an Ethernet Segment-Import Route Target when the IGMP join message is received at a port, of the non-designated forwarder provider edge device, that is associated with an Ethernet Segment Identification for a set of Ethernet communication links between said host device and each of the plurality of provider edge devices; and
sending, by the non-designated forwarder provider edge device, a second route advertisement message that includes an EVPN Instance Route Target when the IGMP join message is received at a port of the non-elected provider edge device that is not associated with any Ethernet Segment Identification.

2. The method according to claim 1 , wherein the first route advertisement message is a Selective Multicast Ethernet Tag route message of Border Gateway Protocol.

3. The method according to claim 1 , wherein the EVPN instance Route Target is a Route-Import Route Target auto-derived from a Virtual Network Instance.

4. The method according to claim 1 , wherein the EVPN instance Route Target is a Route-Import Route Target auto-derived from a Multi-Protocol Label Switching label.

5. The method according to claim 1 , further comprising:
receiving, at the non-designated forwarder provider edge device, a third route advertisement message comprising the Ethernet Segment-Import Route Target;
establishing, by the non-designated forwarder provider edge device, that the Ethernet Segment-Import Route Target matches said Ethernet Segment Identification; and
adding data contained in the third route advertisement message to an IGMP synchronization listing of the non-designated forwarder provider edge device.

6. The method according to claim 5 , further comprising:
when the non-designated forwarder provider edge device becomes elected to be the designated forwarder for said host device, sending a fourth route advertisement message including said Ethernet Segment-Import Route Target and an EVPN Instance Route Target based on said IGMP synchronization listing.

7. The method according to claim 5 , further comprising:
determining whether the Ethernet Segment-Import Route Target matches the Ethernet Segment Identification; and
in response to determining that the Ethernet Segment-Import Route Target does not match the Ethernet Segment Identification, dropping the third route advertisement message.

8. A system for assisting forwarding of multicast traffic over an Ethernet Virtual Private Network (EVPN) fabric from a multicast source to a host device multi-homed to a plurality of provider edge devices, the system comprising:
at least one memory element configured to store computer executable instructions, and
at least one processor coupled to the at least one memory element and configured, when executing the instructions, to:
receive, at a provider edge device not elected, out of said plurality of provider edge devices, to be a designated forwarder for said host device (non-designated forwarder provider edge device), an Internet Group Management Protocol (IGMP) join message;
send, by the non-designated forwarder provider edge device, a first route advertisement message that includes an Ethernet Segment-Import Route Target when the IGMP join message is received at a port, of the non-designated forwarder provider edge device, that is associated with an Ethernet Segment Identification for a set of Ethernet communication links between said host device and each of the plurality of provider edge devices; and
send, by the non-designated forwarder provider edge device, a second route advertisement message that includes an EVPN Instance Route Target when the IGMP join message is received at a port of the non-elected provider edge device that is not associated with any Ethernet Segment Identification.

9. The system according to claim 8 , wherein the EVPN instance Route Target is a Route-Import Route Target auto-derived from a Virtual Network Instance.

10. The system according to claim 8 , wherein the EVPN instance Route Target is a Route-Import Route Target auto-derived from a Multi-Protocol Label Switching label.

11. The system according to claim 8 , wherein the at least one processor is further configured to:
receive, at the non-designated forwarder provider edge device, a third route advertisement message comprising the Ethernet Segment-Import Route Target;
establish, by the non-designated forwarder provider edge device, that the Ethernet Segment-Import Route Target matches said Ethernet Segment Identification; and
add data contained in the third route advertisement message to an IGMP synchronization listing of the non-designated forwarder provider edge device.

12. The system according to claim 11 , wherein the at least one processor is further configured to:
when the non-designated forwarder provider edge device becomes elected to be the designated forwarder for said host device, send a fourth route advertisement message including said Ethernet Segment-Import Route Target and an EVPN Instance Route Target based on said IGMP synchronization listing.

13. The system according to claim 11 , wherein the at least one processor is further configured to:
determine whether the Ethernet Segment-Import Route Target matches the Ethernet Segment Identification; and
in response to determining that the Ethernet Segment-Import Route Target does not match the Ethernet Segment Identification, drop the third route advertisement message.

14. A non-transitory computer-readable storage media encoded with software comprising computer executable instructions which, when executed by a processor at a provider edge device not elected, out of a plurality of provider edge devices, to be a designated forwarder for a host device (non-designated forwarder provider edge device), cause the processor to:
receive an Internet Group Management Protocol (IGMP) join message;
send a first route advertisement message that includes an Ethernet Segment-Import Route Target when the IGMP join message is received at a port, of the non-designated forwarder provider edge device, that is associated with an Ethernet Segment Identification for a set of Ethernet communication links between the host device and each of the plurality of provider edge devices; and
send a second route advertisement message that includes an EVPN Instance Route Target when the IGMP join message is received at a port of the non-elected provider edge device that is not associated with any Ethernet Segment Identification.

15. The non-transitory computer-readable storage media according to claim 14 , wherein the first route advertisement message is a Selective Multicast Ethernet Tag route message of Border Gateway Protocol.

16. The non-transitory computer-readable storage media according to claim 14 , wherein the EVPN instance Route Target is a Route-Import Route Target auto-derived from a Virtual Network Instance.

17. The non-transitory computer-readable storage media according to claim 14 , wherein the EVPN instance Rout

Assignees

• Cisco Tech Inc

Inventors

• Kanjariya Mitesh Mukesh
• Gupta Ashutosh
• Pandey Manoj Kumar

Classifications

• H04L12/4641

  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 title

• H04L12/185

  with management of multicast group membership · CPC title

• H04L45/021

  Ensuring consistency of routing table updates, e.g. by using epoch numbers · CPC title

• H04L12/4662

  wherein a VLAN tag represents a service instance, e.g. I-SID in PBB · CPC title

• H04L45/50 Primary

  using label swapping, e.g. multi-protocol label switch [MPLS] · CPC title