Signaling aliasing capability in data centers

Patent metadata

Field	Value
Publication number	US-2016134528-A1
Application number	US-201414585841-A
Country	US
Kind code	A1
Filing date	Dec 30, 2014
Priority date	Nov 10, 2014
Publication date	May 12, 2016
Grant date	—

Abstract

Techniques are described for signaling aliasing capability between routers in a multi-tenant data center that uses VPNs, such as Ethernet VPNs. In the multi-tenant data center, two or more PE routers may be connected to a CE router by a multi-homed L2 segment in an all-active mode. Aliasing refers to the ability of a PE router to signal that it can reach a given multi-homed L2 segment even when the PE router has learned no MAC addresses over that multi-homed L2 segment. The PE routers on the multi-homed L2 segment advertise aliasing capability using a route advertisement on a per-L2 segment basis. When the multi-tenant data center uses global VPN identifiers, no additional information is needed by a remote PE to build an ECMP next hop to the PE routers that support aliasing, and transmission of a route advertisement on a per-VPN basis may be suppressed.

First claim

What is claimed is:

1 . A method comprising:
establishing, between a first site and a second site of a multi-tenant data center, an Ethernet virtual private network (EVPN) including two or more provider edge (PE) routers connected to a customer edge (CE) router of the first site on a multi-homed Ethernet segment (ES) in an all-active mode, and at least one remote PE router; receiving, by a first PE router of the two or more PE routers on the multi-homed ES from the CE router, a packet with a media access control (MAC) address associated with the CE router; sending, by the first PE router to the at least one remote PE router, a MAC route advertisement including the MAC address associated with the CE router; and sending, by at least a second PE router of the two or more PE routers on the multi-homed ES to the at least one remote PE router, a per-ES auto-discovery (AD) route advertisement indicating whether the second PE router supports aliasing for the multi-homed ES.

2 . The method of claim 1 , wherein the EVPN comprises an EVPN overlay with Virtual Extensible Local Area Network (VXLAN) encapsulation over an Internet Protocol (IP) underlay network that uses a global Virtual Network Identifier (VNI), and wherein sending the MAC route advertisement comprises sending, by the first PE router to the remote PE router, the global VNI included in the MAC route advertisement.

3 . The method of claim 2 , further comprising suppressing, by the second PE router, transmission of a per-EVPN instance (EVI) AD route advertisement to the remote PE router.

4 . The method of claim 2 , further comprising, based on the per-ES AD route advertisement indicating that the second PE router supports aliasing for the multi-homed ES, receiving, by the second PE router from the remote PE router according to an Equal Cost Multipath (ECMP) next hop built using the global VNI, data packets destined for the MAC address associated with the CE router.

5 . The method of claim 1 , wherein the EVPN comprises one of an EVPN overlay with Virtual Extensible Local Area Network (VXLAN) encapsulation over an Internet Protocol (IP) underlay network that uses local Virtual Network Identifiers (VNIs) or a Multi-Protocol Label Switching (MPLS) based EVPN, the method further comprising:
based on the second PE router supporting aliasing for the multi-homed ES, sending, by the second PE router to the remote PE router, a per-EVPN instance (EVI) AD route advertisement indicating one of the local VNI or a MPLS aliasing label; and receiving, by the second PE router from the remote PE router according to an Equal Cost Multipath (ECMP) next hop built using the one of the local VNI or the MPLS aliasing label, data packets destined for the MAC address associated with the CE router.

6 . The method of claim 1 , wherein the per-ES AD route advertisement sent by the second PE router includes an Ethernet Segment Identifier (ESI) Label Extended Community with an aliasing bit, wherein the aliasing bit being set indicates that the second PE router supports aliasing for the multi-homed ES, and the aliasing bit being reset indicates that the second PE router does not support aliasing for the multi-homed ES.

7 . The method of claim 1 , wherein sending the per-ES AD route advertisement comprises sending, by at least the first PE router and the second PE router to the remote PE router, a per-ES AD route advertisement indicating whether the respective PE router supports aliasing for the multi-homed ES.

8 . The method of claim 1 , wherein sending the per-ES AD route advertisement comprises sending, by each of the two or more PE routers on the multi-homed ES to the remote PE router, a per-ES AD route advertisement indicating whether the respective PE router supports aliasing for the multi-homed ES.

9 . A system comprising:
two or more provider edge (PE) routers included in an Ethernet virtual private network (EVPN) established between a first site and a second site of a multi-tenant data center, the two or more PE routers connected to a customer edge (CE) router of the first site on a multi-homed Ethernet segment (ES) in an all-active mode; a first PE router of the two or more PE routers on the multi-homed ES configured to receive, from the CE router, a packet with a media access control (MAC) address associated with the CE router, and send, to at least one remote PE router included in the EVPN, a MAC route advertisement including the MAC address associated with the CE router; and a second PE router of the two or more PE routers on the multi-homed ES configured to send, to the at least one remote PE router, a per-ES auto-discovery (AD) route advertisement indicating whether the second PE router supports aliasing for the multi-homed ES.

10 . The system of claim 9 , wherein the EVPN comprises an EVPN overlay with Virtual Extensible Local Area Network (VXLAN) encapsulation over an Internet Protocol (IP) underlay network that uses a global Virtual Network Identifier (VNI), and wherein the first PE router is configured to send, to the remote PE router, the global VNI included in the MAC route advertisement.

11 . The system of claim 10 , wherein the second PE router is configured to suppress transmission of a per-EVPN instance (EVI) AD route advertisement to the remote PE router.

12 . The system of claim 10 , wherein the remote PE router is configured to, based on the per-ES AD route advertisement indicating that the second PE router supports aliasing for the multi-homed ES, receive, from the remote PE router according to an Equal Cost Multipath (ECMP) next hop built using the global VNI, data packets destined for the MAC address associated with the CE router.

13 . The system of claim 9 , wherein the EVPN comprises one of an EVPN overlay with Virtual Extensible Local Area Network (VXLAN) encapsulation over an Internet Protocol (IP) underlay network that uses local Virtual Network Identifiers (VNIs) or a Multi-Protocol Label Switching (MPLS) based EVPN, wherein the second PE is configured to:
based on the second PE router supporting aliasing for the multi-homed ES, send, to the remote PE router, a per-EVPN instance (EVI) AD route advertisement indicating one of the local VNI or a MPLS aliasing label; and receive, from the remote PE router according to an Equal Cost Multipath (ECMP) next hop built using the one of the local VNI or the MPLS aliasing label, data packets destined for the MAC address associated with the CE router.

14 . The system of claim 9 , wherein the per-ES AD route advertisement sent by the second PE router includes an Ethernet Segment Identifier (ESI) Label Extended Community with an aliasing bit, wherein the aliasing bit being set indicates that the second PE router supports aliasing for the multi-homed ES, and the aliasing bit being reset indicates that the second PE router does not support aliasing for the multi-homed ES.

15 . The system of claim 9 , wherein each of the first PE router and the second PE router are configured to send, to the remote PE router, a per-ES AD route advertisement indicating whether the respective PE router supports aliasing for the multi-homed ES.

16 . The system of claim 9 , wherein each of the two or more PE routers on the multi-homed ES are configured to send, to the remote PE router, a per-ES AD route advertisement indicating whether the respective PE router supports aliasing for the multi-homed ES.

17 . A method comprising:
establishing, between a first site and a second site of a multi-tenant data center, an Ethernet virtual private network (EVPN) including two or more provide

Assignees

• Juniper Networks Inc

Inventors

• Lin Wen
• Venkatraman Vasudevan
• Drake John E

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

• H04L45/66 Primary

  Layer 2 routing, e.g. in Ethernet based MAN's · CPC title

• H04L45/04

  Interdomain routing, e.g. hierarchical routing · CPC title

• H04L61/6022

  Electricity · mapped topic

• H04L45/74 Primary

  Address processing for routing · CPC title