Building an efficient EVPN VXLAN broadcast domain based on workload

1 . A method, comprising:

determining a replication threshold for a device in an overlay network, wherein the device operates as a tunnel endpoint, and wherein the replication threshold indicates a capacity of replication resources of the device;

obtaining a current replication count for the device corresponding to a respective virtual extensible local area network (VXLAN);

selecting a replication type for a broadcast domain specific to the device and the respective VXLAN based on the replication threshold and the current replication count, wherein the replication type indicates one of:

a first type associated with an ingress replication broadcast domain comprising unicast tunnels;

a second type associated with an underlay multicast broadcast domain comprising multicast tunnels; and

a third type associated with a hybrid broadcast domain comprising a combination of the first type and the second type; and

creating the broadcast domain specific to the device and the respective VXLAN based on the selected replication type.

2 . The method of claim 1 , wherein determining the replication threshold for the device comprises determining at least one of:

a configuration set by an administrator based on a capacity of the device; and

maximum supported capabilities of the device.

3 . The method of claim 1 ,

wherein the overlay network comprises an Ethernet Virtual Private Network (EVPN), and

wherein the device operates as a virtual tunnel endpoint (VTEP) in the EVPN.

4 . The method of claim 3 , further comprising:

wherein the replication threshold is stored by the device in a data structure based on control packets transmitted in the EVPN.

5 . The method of claim 1 , wherein selecting the replication type comprises:

selecting the first type in response to the current replication count being less than or equal to the replication threshold; and

selecting the second type in response to the current replication count being greater than the replication threshold.

6 . The method of claim 5 , wherein subsequent to selecting the second type, the method further comprises:

iterating through remote endpoints advertised in the broadcast domain specific to the device and the respective VXLAN by:

determining whether a respective remote endpoint is capable of ingress replication based on the first type of broadcast domain; and

in response to determining that the respective remote endpoint is capable of ingress replication, selecting the third type as the replication type for the broadcast domain specific to the device and the respective VXLAN.

7 . The method of claim 6 , wherein creating the broadcast domain comprises:

in response to selecting the first type, adding a unicast tunnel to the ingress replication broadcast domain;

in response to selecting the second type, adding a multicast tunnel to the underlay multicast broadcast domain; and

in response to selecting the third type:

adding, to the hybrid broadcast domain, a unicast tunnel associated with the respective remote endpoint capable of ingress replication; and

adding, to the hybrid broadcast domain, a multicast tunnel associated with a multicast group for the respective remote endpoint.

8 . The method of claim 1 , further comprising:

communicating the replication threshold to remote tunnel endpoints via a Border Gateway Protocol (BGP) message.

9 . The method of claim 8 ,

wherein the BGP message comprises a BGP Open message with an optional parameter, and

wherein the optional parameter comprises:

a code indicating a capability as the replication threshold;

a length indicating a size of the optional parameter; and

a value of the replication threshold.

10 . A computer system, comprising:

a processor; and

a storage device storing instructions to:

identify a replication threshold for a device in an overlay network, wherein the device operates as a tunnel endpoint, and wherein the replication threshold indicates a capacity of replication resources of the device;

determine a current replication count for the device corresponding to a respective virtual extensible local area network (VXLAN);

define, for a broadcast domain specific to the device and the respective VXLAN, a replication type based on the replication threshold and the current replication count, wherein the replication type indicates one of:

a first type associated with an ingress replication broadcast domain comprising unicast tunnels;

a second type associated with an underlay multicast broadcast domain comprising multicast tunnels; and

a third type associated with a hybrid broadcast domain comprising a combination of the first type and the second type; and

create the broadcast domain specific to the device and the respective 18 VXLAN based on the defined replication type.

11 . The computer system of claim 10 , wherein identifying the replication threshold for the device comprises determining at least one of:

a configuration set by an administrator based on a capacity of the device; and

maximum supported capabilities of the device.

12 . The computer system of claim 10 ,

wherein the overlay network comprises an Ethernet Virtual Private Network (EVPN), and

wherein the device operates as a virtual tunnel endpoint (VTEP) in the EVPN.

13 . The computer system of claim 10 , wherein defining the replication type for the broadcast domain comprises:

selecting the first type in response to the current replication count being less than or equal to the replication threshold; and

selecting the second type in response to the current replication count being greater than the replication threshold.

14 . The computer system of claim 13 , wherein subsequent to selecting the second type, the instructions are further to:

iterate through remote endpoints advertised in the broadcast domain specific to the device and the respective VXLAN by:

determining whether a respective remote endpoint is capable of ingress replication based on the first type of broadcast domain; and

in response to determining that the respective remote endpoint is capable of ingress replication, selecting the third type as the replication type for the broadcast domain specific to the device and the respective VXLAN.

15 . The computer system of claim 14 , wherein creating the broadcast domain comprises:

adding a unicast tunnel to the ingress replication broadcast domain responsive to selecting the first type;

adding a multicast tunnel to the underlay multicast broadcast domain responsive to selecting the second type; and

responsive to selecting the third type:

adding, to the hybrid broadcast domain, a unicast tunnel associated with the respective remote endpoint capable of ingress replication; and

adding, to the hybrid broadcast domain, a multicast tunnel associated with a multicast group for the respective remote endpoint.

16 . The computer system of claim 10 , the instructions further to:

communicate the replication threshold to remote tunnel endpoints via a Border Gateway Protocol (BGP) Open message which includes an optional parameter,

wherein the optional parameter comprises:

a code indicating a capability as the replication threshold;

a length indicating a size of the optional parameter; and

a value of the replication threshold.

17 . A non-transitory computer-readable storage medium storing instructions to:

determine a replication threshold for a device in an overlay network, wherein the replication threshold indicates a capacity of replication resources of the device;

obtain a current replication count for the device corresponding to a respective virtual extensible local area network (VXLAN), wherein the device operates as a tunnel endpoint;

select a replication type for a broadcast domain specific to the device and the respective VXLAN based on the capacity of replication resources and the current replication count, wherein the replication type indicates one or more of:

a first type associated with an ingress replication broadcast domain comprising unicast tunnels;

a second type associated with an underlay multicast broadcast domain comprising multicast tunnels; and

a third type associated with a hybrid broadcast domain comprising a combination of the first type and the second type; and

create the broadcast domain specific to the device and the respective VXLAN based on the selected replication type.

18 . The non-transitory computer-readable storage medium of claim 17 , wherein selecting the replication type comprises:

selecting the first type in response to the current replication count being less than or equal to the replication threshold; and

selecting the second type in response to the current replication count being greater than the replication threshold.

19 . The non-transitory computer-readable storage medium of claim 18 , wherein subsequent to selecting the second type, the instructions are further to:

iterate through remote endpoints advertised in the broadcast domain specific to the device and the respective VXLAN by:

determining whether a respective remote endpoint is capable of ingress replication based on the first type of broadcast domain; and

in response to determining that the respective remote endpoint is capable of ingress replication, selecting the third type as the replication type for the broadcast domain specific to the device and the respective VXLAN.

20 . The non-transitory computer-readable storage medium of claim 17 , the instructions further to:

communicate the replication threshold to remote tunnel endpoints via a Border Gateway Protocol (BGP) Open message based on an optional parameter.