Interoperability between symmetric and asymmetric EVPN IRB modes

1. A method comprising:

receiving an Ethernet Virtual Private Network (EVPN) Media Access Control/Internet Protocol (MAC/IP) Advertisement Route from a Provider Edge (PE) router;

examining a Multiprotocol Label Switching (MPLS) label of the EVPN MAC/IP Advertisement Route;

determining that Internet Protocol Virtual Route Forwarding (IP-VRF) attributes are not carried in the MPLS label of the EVPN MAC/IP Advertisement Route;

adding, based on information in the EVPN MAC/IP Advertisement Route, an Address Resolution Protocol (ARP) entry to an ARP table, the ARP entry including at least one of a MAC address and an IP address from the EVPN MAC/IP Advertisement Route; and

adding, in response to the determining that IP-VRF attributes are not carried in the MPLS label, a MAC entry to a MAC table identified by a Border Gateway Protocol (BGP) target of the MAC address.

2. The method of claim 1 , further comprising:

determining that Internet Protocol Virtual Route Forwarding (IP-VRF) attributes are carried in the MPLS label of the EVPN MAC/IP Advertisement Route; and

adding a host IP route with Virtual Route Forwarding (VRF) to an IP-VRF table per Multiprotocol Label Switching (MPLS) label; and

adding, in response to the determining that IP-VRF attributes are carried in the MPLS label, a MAC entry to a MAC table identified by a BGP target of the MAC address.

3. The method of claim 2 , wherein adding the host IP route with Virtual Route Forwarding (VRF) to an IP-VRF table is via Virtual Extensible Local Area Network (VXLAN) Network Identifier (VNI) encapsulation.

4. The method of claim 1 , wherein the Ethernet Virtual Private Network (EVPN) MAC/IP Advertisement Route can have Layer 2 or Layer 3 information.

5. The method of claim 1 , wherein receiving the EVPN MAC/IP Advertisement Route occurs at an ingress switch.

6. A Provider Edge (PE) system comprising:

one or more processors; and

a computer-readable storage medium having stored therein instructions which, when executed by the one or more processors, cause the one or more processors to perform operations comprising:

receiving an Ethernet Virtual Private Network (EVPN) Media Access Control/Internet Protocol (MAC/IP) Advertisement Route from a first PE router;

determining that the EVPN MAC/IP Advertisement Route is associated with an asymmetric Integrated Routing and Bridging (IRB) mode based on a Multiprotocol Label Switching (MPLS) label of the EVPN MAC/IP Advertisement Route;

adding an Address Resolution Protocol (ARP) entry to an ARP table from information in the EVPN MAC/IP Advertisement Route that includes both a MAC address and an IP address from the EVPN MAC/IP Advertisement Route; and

adding a MAC entry to a MAC table identified by a Border Gateway Protocol (BGP) target of the MAC address.

7. The Provider Edge (PE) system of claim 6 , further comprising:

determining that Internet Protocol Virtual Route Forwarding (IP-VRF) attributes are carried in the MPLS label of the Ethernet Virtual Private Network (EVPN) MAC/IP Advertisement Route; and

adding a host IP route with VRF to a IP-VRF table per MPLS label; and

adding a MAC entry to a MAC table identified by a BGP target of the MAC address.

8. The Provider Edge (PE) system of claim 7 , further comprising:

building a second Ethernet Virtual Private Network (EVPN) MAC/IP Advertisement Route from the information; and

advertising the second EVPN MAC/IP Advertisement Route to a second PE device.

9. The Provider Edge (PE) system of claim 6 , further comprising:

building a second Ethernet Virtual Private Network (EVPN) MAC/IP Advertisement Route from the information; and

advertising the second EVPN MAC/IP advertisement to a second PE device.

10. The Provider Edge (PE) device of claim 9 , wherein the advertising the second Ethernet Virtual Private Network (EVPN) MAC/IP Advertisement Route is advertised with two route targets, one for the Media Access Control Virtual Route Forwarding (MAC-VRF) and one for Internet Protocol Virtual Route Forwarding (IP-VRF) when communication is between different IP subnets.

11. The Provider Edge (PE) system of claim 6 , wherein the Ethernet Virtual Private Network (EVPN) MAC/IP Advertisement Route can have Layer 2 or Layer 3 information.

12. The Provider Edge (PE) system of claim 6 , wherein receiving the EVPN MAC/IP Advertisement Route occurs at an ingress switch.

13. The Provider Edge (PE) system of claim 6 , wherein adding the Host IP route is via encapsulation per Virtual Extensible Local Area Network (VXLAN) Network Identifier (VNI) rather than MPLS label.

14. A non-transitory computer-readable storage medium having stored therein instructions which, when executed by one or more processors, cause the one or more processors to perform operations comprising:

receiving an Ethernet Virtual Private Network (EVPN) Media Access Control/Internet Protocol (MAC/IP) Advertisement Route from a first Provider Edge (PE) router;

determining that the EVPN MAC/IP Advertisement Route is asymmetric based on a lack of Internet Protocol Virtual Route Forwarding (IP-VRF) attributes associated with the EVPN MAC/IP Advertisement Route; and

creating forwarding information, based on the information in the EVPN MAC/IP Advertisement Route, to provide inter-subnet connectivity; and

advertising a second EVPN MAC/IP Advertisement Route with the forwarding information to a second PE router when communication is between different IP subnets.

15. The non-transitory computer-readable storage medium of claim 14 , wherein creating forwarding information is based on the information in the EVPN MAC/IP Advertisement Route, to provide inter-subnet connectivity comprises:

adding an Address Resolution Protocol (ARP) entry to an ARP table from information in the EVPN MAC/IP Advertisement Route that includes both the MAC address and the IP address from the EVPN MAC/IP Advertisement Route, in response to the determining that the IP-VRF attributes are not carried in an Multiprotocol Label Switching (MPLS label); and

adding a MAC entry to a MAC table identified by a Border Gateway Protocol (BGP) target of the MAC address, in response to the determining that IP-VRF attributes are not carried in the MPLS label.

16. The non-transitory computer-readable storage medium of claim 14 , wherein creating forwarding information, based on the information in the EVPN MAC/IP Advertisement Route, to provide inter-subnet connectivity comprises:

adding a host IP route with Virtual Route Forwarding (VRF) to a IP-VRF table per Multiprotocol Label Switching (MPLS) encapsulation, in response to determining that the IP-VRF attributes are carried in an MPLS label; and

adding a MAC entry to a MAC table identified by a BGP target of the MAC address in response to the determining that IP-VRF attributes are carried in the MPLS label.

17. The non-transitory computer-readable storage medium of claim 16 , wherein adding the host IP route with Virtual Route Forwarding (VRF) to an IP-VRF table is via Virtual Extensible Local Area Network (VXLAN) Network Identifier (VNI) encapsulation.

18. The non-transitory computer-readable storage medium of claim 14 , wherein the Ethernet Virtual Private Network (EVPN) MAC/IP Advertisement Route can have Layer 2 or Layer 3 information.

19. The non-transitory computer-readable storage medium of claim 14 , wherein receiving the EVPN MAC/IP Advertisement Route occurs at an ingress switch.

20. The non-transitory computer-readable storage medium of claim 14 , wherein the second PE router could be an asymmetric Integrated Routing and Bridging (IRB) PE or a symmetric IRB PE.