Ethernet virtual private network using segment routing
In one embodiment, Ethernet Virtual Private Network (EVPN) is implemented using Internet Protocol Version 6 (IPv6) Segment Routing (SRv6) underlay network and SRv6-enhanced Border Gateway Protocol (BGP) signaling. A particular route associated with a particular Internet Protocol Version 6 (IPv6) Segment Routing (SRv6) Segment Identifier (SID) is advertised in a particular route advertisement message of a routing protocol (e.g., BGP). The SID includes encoding representing a particular Ethernet Virtual Private Network (EVPN) Layer 2 (L2) flooding Segment Routing end function of the particular router and a particular Ethernet Segment Identifier (ESI), with the particular SID including a routable prefix to the particular router. The particular router receives a particular packet including the particular SID; and in response, the particular router performs the particular EVPN end function on the particular packet.
1. An apparatus comprising:
network interfaces configured to send and receive packets in a network;
one or more memory devices; and
one or more processors operatively coupled to the one or more network interfaces and the one or more memory devices;
wherein the one or more processors are configured to cause the apparatus to perform processing operations, the processing operations comprising:
maintaining in the one or more memory devices, forwarding information, the forwarding information associated with an Internet Protocol Version 6 (IPv6) Segment Routing (SRv6) Segment Identifier (SID), wherein the SID comprises an encoding of an Ethernet Virtual Private Network (EVPN) Layer 2 (L2) flooding Segment Routing end function and an encoding of an Ethernet Segment Identifier (ESI);
receiving, at a first network interface of the network interfaces, an IPv6 packet, the IPv6 packet comprising an SRv6 header, the SRv6 header comprising a destination address;
responsive to the destination address comprising the SID,
performing behavior of the EVPN L2 flooding segment routing end function,
wherein the behavior of the EVPN L2 flooding segment routing end function comprises:
decapsulating an Ethernet frame from the received IPv6 packet by removing the SRv6 header, and
forwarding the Ethernet frame from each of a set of output network interfaces of the network interfaces identified in a L2 table of the forwarding information,
wherein the forwarding excludes one or more of the network interfaces associated with the ESI;
wherein the Ethernet frame is sent from at least one of the network interfaces.
2. The apparatus of claim 1 wherein the processing operations further comprise advertising the forwarding information in a route advertisement message of a routing protocol.
3. The apparatus of claim 2 wherein the routing protocol is Border Gateway Protocol (BGP).
4. The apparatus of claim 3 , wherein the route advertisement message advertises a BGP route type 1, 2, 3, or 5, and associated with a particular SRv6-VPN Type Length Value (TLV) including the SID.
5. The apparatus of claim 4 , wherein the route advertisement message identifies that SRv6 EVPN is supported as identified by the SRv6-VPN TLV.
6. The apparatus of claim 1 , wherein the received IPv6 Packet comprises a Segment Routing Header (SRH) including the SID as the currently active SID.
7. The apparatus of claim 1 , wherein the SID is a 128-bit IPv6 address.
8. A method comprising:
maintaining in one or more of memory devices, forwarding information, the forwarding information associated with an Internet Protocol Version 6 (IPv6) Segment Routing (SRv6) Segment Identifier (SID), wherein the SID comprises an encoding of an Ethernet Virtual Private Network (EVPN) Layer 2 (L2) flooding Segment Routing end function and an encoding of an Ethernet Segment Identifier (ESI);
receiving, at a first network interface of network interfaces, an IPv6 packet, the IPv6 packet comprising an SRv6 header, the SRv6 header comprising a destination address;
responsive to the destination address comprising the SID, performing behavior of the EVPN L2 flooding Segment Routing end function, wherein the behavior of the EVPN L2 flooding Segment Routing end function comprises:
decapsulating an Ethernet frame from the received IPv6 packet by removing the SRv6 header, and
forwarding the Ethernet frame from each of a set of output network interfaces of the network interfaces identified in a L2 table of the forwarding information,
wherein the forwarding excludes one or more of the network interfaces associated with the ESI;
wherein the Ethernet frame is sent from at least one of the network interfaces.
9. The method of claim 8 further comprising advertising the forwarding information in a received route advertisement message of a routing protocol.
10. The method of claim 9 wherein the routing protocol is Border Gateway Protocol (BGP).
11. The method of claim 10 , wherein the route advertisement message advertises a BGP route type 1, 2, 3, or 5, and associated with a particular SRv6-VPN Type Length Value (TLV) including the SID.
12. The method of claim 11 , wherein the route advertisement message identifies that SRv6 EVPN is supported as identified by the SRv6-VPN TLV.
13. The method of claim 8 , wherein the received IPv6 Packet comprises a Segment Routing Header (SRH) including the SID as the currently active SID.
14. The method of claim 8 , wherein the SID is a 128-bit IPv6 address.
15. The method of claim 8 , further comprising:
receiving, by an ingress router, an route advertisement message;
receiving, by the ingress router, the Ethernet frame;
encapsulating the Ethernet frame into the IPv6 packet by the ingress router; and
sending the IPv6 packet into a network by the ingress router.