Changing the Distributed Router Interfaces' MAC Address

All logical router interfaces in NSX-T and NSX-v setups have the same MAC address (02:50:56:56:44:52). Starting with NSX-T Data Center 3.0.2, you can change this address in NSX-T to avoid issues when migrating VMs from an NSX-v setup to an NSX-T setup.

Changing the MAC address involves making two API calls.

If you have not created any transport node, make the following GET API call. For example:

GET https://10.40.79.126/api/v1/global-configs/RoutingGlobalConfig

Response:
{
  "l3_forwarding_mode" : "IPV4_ONLY",
  "logical_uplink_mtu" : 1500,
  "vdr_mac" : "02:50:56:56:44:77",
  "vdr_mac_nested" : "02:50:56:56:44:52",
  "allow_changing_vdr_mac_in_use" : true,
  "resource_type" : "RoutingGlobalConfig",
  "id" : "49b261fe-f4e4-46ad-958c-da9cb4271e32",
  "display_name" : "49b261fe-f4e4-46ad-958c-da9cb4271e32",
  "_create_user" : "system",
  "_create_time" : 1595313890595,
  "_last_modified_user" : "admin",
  "_last_modified_time" : 1595465694142,
  "_system_owned" : false,
  "_protection" : "NOT_PROTECTED",
  "_revision" : 14
}

Take the response of the call, change the vdr_mac value, and use it to make the following PUT API call. For example:

PUT  https://10.40.79.126/api/v1/global-configs/RoutingGlobalConfig
{
  "l3_forwarding_mode" : "IPV4_ONLY",
  "logical_uplink_mtu" : 1500,
  "vdr_mac" : "02:50:56:56:44:99",
  "vdr_mac_nested" : "02:50:56:56:44:53",
  "allow_changing_vdr_mac_in_use" : true,
  "resource_type" : "RoutingGlobalConfig",
  "id" : "49b261fe-f4e4-46ad-958c-da9cb4271e32",
  "display_name" : "49b261fe-f4e4-46ad-958c-da9cb4271e32",
  "_create_user" : "system",
  "_create_time" : 1595313890595,
  "_last_modified_user" : "admin",
  "_last_modified_time" : 1595465694142,
  "_system_owned" : false,
  "_protection" : "NOT_PROTECTED",
  "_revision" : 14
}

Response:
{
  "l3_forwarding_mode" : "IPV4_ONLY",
  "logical_uplink_mtu" : 1500,
  "vdr_mac" : "02:50:56:56:44:99",
  "vdr_mac_nested" : "02:50:56:56:44:53",
  "allow_changing_vdr_mac_in_use" : true,
  "resource_type" : "RoutingGlobalConfig",
  "id" : "49b261fe-f4e4-46ad-958c-da9cb4271e32",
  "display_name" : "49b261fe-f4e4-46ad-958c-da9cb4271e32",
  "_create_user" : "system",
  "_create_time" : 1595313890595,
  "_last_modified_user" : "admin",
  "_last_modified_time" : 1595466163148,
  "_system_owned" : false,
  "_protection" : "NOT_PROTECTED",
  "_revision" : 15
}

If you have already created transport nodes, make the same GET and PUT API calls, except that for the PUT call, set the parameter allow_changing_vdr_mac_in_use to true.