Assisted replication in software defined network

1. A method comprising:

receiving, by a controller, a first multicast route and a second multicast route;

in response to determining that the first multicast route is an assisted replication route, adding, by the controller, a first nexthop specified by the first multicast route to a list of nexthops for Broadcast, Unknown-Unicast, and Multicast (BUM) traffic;

in response to determining that the second multicast route is not the assisted replication route, refraining from adding, by the controller, a second nexthop specified by the second multicast route to the list of nexthops for BUM traffic; and

configuring, by the controller, after adding the first nexthop, a virtual router based on the list of nexthops.

2. The method of claim 1 , wherein receiving the first multicast route and the second multicast route comprises:

receiving one or more router advertisements of the first multicast route and the second multicast route.

3. The method of claim 2 , wherein the one or more router advertisements are compliant with Border Gateway Protocol (BGP) Auto-Discovery (AD) procedures.

4. The method of claim 2 , further comprising:

determining, by the controller, from the one or more router advertisements, a first indication specifying that the first multicast route is designated with a first tunnel type corresponding to an assisted replication route type, and determining that the first multicast route is the assisted replication route in response to the first indication; and

determining, by the controller, from the one or more router advertisements, a second indication specifying that the second multicast route is designated with a second tunnel type that does not correspond to the assisted replication route type, and determining that the second multicast route is not the assisted replication route in response to the second indication.

5. The method of claim 1 , wherein the virtual router is configured for Ethernet Virtual Private Network Assisted Multicast Replication.

6. The method of claim 1 , further comprising:

receiving, by the controller, one or more multicast group membership messages that identify the virtual router as a source of a multicast group; and

wherein configuring the virtual router comprises configuring the virtual router to replicate the BUM traffic using the list of nexthops.

7. The method of claim 6 , wherein configuring the virtual router comprises configuring the virtual router with a multicast replication tree for the multicast group using the list of nexthops, wherein the multicast replication tree is an overlay distribution tree for the multicast group.

8. The method of claim 7 , wherein the multicast replication tree is an Edge Replicated Multicast (ERM) tree configured for Edge Replicated Multicast for Virtual Private Networking (ERMVPN).

9. The method of claim 8 , wherein the one or more multicast group membership messages comprises one or more ERMVPN join messages.

10. The method of claim 9 , wherein receiving the one or more ERMVPN join messages comprises receiving the one or more ERMVPN join messages using an Extensible Messaging and Presence Protocol (XMPP).

11. The method of claim 1 , wherein the first multicast route comprises an assisted replicator route extending between a Top-Of-Rack (TOR) switch and a first chassis switch and wherein the second multicast route comprises a normal Inclusive Provider Multicast Service Interface (I-PMSI) inclusive multicast route extending between the TOR switch and a second chassis switch different from the first chassis switch.

12. The method of claim 11 , further comprising configuring, by the controller, the first chassis switch to forward the BUM traffic to a designated virtual router of the one or more virtual routers, wherein the designated virtual router is configured to replicate the BUM traffic.

13. The method of claim 11 , wherein the one or more virtual routers comprises a plurality of receivers, the method further comprising configuring, by the controller, the first chassis switch to replicate the BUM traffic to the plurality of receivers.

14. A controller comprising one or more processors configured to:

receive a first multicast route and a second multicast route;

in response to a determination that the first multicast route is an assisted replication route, add a first nexthop specified by the first multicast route to a list of nexthops for Broadcast, Unknown-Unicast, and Multicast (BUM) traffic;

in response to a determination that the second multicast route is not the assisted replication route, refrain from adding a second nexthop specified by the second multicast route to the list of nexthops for BUM traffic; and

configure, after adding the first nexthop, a virtual router based on the list of nexthops.

15. The controller of claim 14 , wherein, to receive the first multicast route and the second multicast route, the controller is configured to:

receive one or more router advertisements of the first multicast route and the second multicast route.

16. The controller of claim 15 , wherein the one or more router advertisements are compliant with Border Gateway Protocol (BGP) Auto-Discovery (AD) procedures.

17. The controller of claim 15 , wherein the controller is configured to:

determine, from the one or more router advertisements, a first indication specifying that the first multicast route is designated with a first tunnel type corresponding to an assisted replication route type, and determine that the first multicast route is the assisted replication route in response to the first indication; and

determine, from the one or more router advertisements, a second indication specifying that the second multicast route is designated with a second tunnel type that does not correspond to the assisted replication route type, and determine that the second multicast route is not the assisted replication route in response to the second indication.

18. The controller of claim 14 , wherein the virtual router is configured for Ethernet Virtual Private Network Assisted Multicast Replication.

19. The controller of claim 14 , wherein the controller is configured to:

receive one or more multicast group membership messages that identify the virtual router as a source of a multicast group; and

wherein, to configure the virtual router, the controller is configured to configure the virtual router to replicate the BUM traffic using the list of nexthops.

20. A non-transitory computer-readable non-transitory storage medium having stored thereon instructions that, when executed, cause a controller to:

receive a first multicast route and a second multicast route;

in response to a determination that the first multicast route is an assisted replication route, add a first nexthop specified by the first multicast route to a list of nexthops for Broadcast, Unknown-Unicast, and Multicast (BUM) traffic;

in response to a determination that the second multicast route is not the assisted replication route, refrain from adding a second nexthop specified by the second multicast route to the list of nexthops for BUM traffic; and

configure, after adding the first nexthop, a virtual router based on the list of nexthops.