To enable access between your VMs and the outside world, you can configure an external BGP (eBGP) connection between a tier-0 logical router and a router in your physical infrastructure.

About this task

When configuring BGP, you must configure a local Autonomous System (AS) number for the tier-0 logical router. For example, the following topology shows the local AS number is 64510. You must also configure the remote AS number of the physical router. In this example, the remote AS number is 64511. The remote neighbor IP address is The neighbor must be in the same IP subnet as the uplink on the tier-0 logical router. BGP multihop is not supported.

For test purposes, the address is configured on the external router loopback interface.


Router ID used for forming BGP sessions on an edge node is autoselected from the IP addresses configured on the uplinks of a tier-0 logical router. BGP sessions on an edge node can flap when router ID changes. This can happen when the IP address auto-selected for router ID is deleted or the logical router port on which this IP is assigned is deleted.

Figure 1. BGP Connection Topology
BGP connection topology diagram



  1. From your browser, log in to an NSX Manager at https://nsx-manager-ip-address.
  2. Select Routing from the navigation panel.
  3. Select the tier-0 logical router.
  4. Click the Routing tab and select BGP from the drop-down menu.
  5. Click Edit to configure the local AS number and click Save.

    For example, 64510.

  6. Click the Status toggle button to enable BGP.

    The Status button must be appear as Enabled.

  7. (Optional) Configure route aggregation, enable graceful restart, and enable ECMP.

    Graceful restart is only supported if the edge cluster associated with the tier-0 router has only one edge node.

  8. Click Save.
  9. Click Add under the Neighbors section to add a BGP neighbor.
  10. Enter the neighbor IP address.

    For example,

  11. (Optional) Select a local address from the drop-down menu.
  12. Enter the remote AS number.

    For example, 64511.

  13. (Optional) Configure the timers (keep alive time and hold down time) and a password.
  14. (Optional) Add an address family and configure route filtering and route maps.

What to do next

Test whether BGP is working properly. See Verify BGP Connections from a Tier-0 Service Router.