Connecting Two NSX Instances with BGP

This quick article focusing on Connecting 2 NSX EDGEs via dynamic routing protocol. BGP (Border Gateway Protocol) in this case.

Connecting two NSX instances using BGP is an essential practice in larger, distributed network environments. BGP helps with dynamic routing between multiple NSX instances, enabling them to share routing information and automatically adjust paths in case of network failures.

Initial requirements:

• Ensure both NSX instances are deployed and operational.
• The NSX Edge devices should be configured and ready to support BGP.
• IP connectivity between the two NSX Edge routers in place. Check connectivity with ICMP for example.
• A BGP ASN (Autonomous System Number) for each NSX instance wil be configured. Make sure you planning it properly. Use ASN from 65XXX.

Steps to Connect Two NSX Instances with BGP

1. Login to NSX Manager: Access the NSX Manager web interface of both NSX instances.

2. Configure BGP on NSX Edge: Navigate to the NSX Edge configuration page on both instances. You will need to configure the BGP settings on the Edge routers that are connected to each network.

   • Go to System > Routing > BGP.
   • Click Add to create a new BGP configuration.

3. Assign BGP ASN: On each NSX Edge, specify the BGP ASN (Autonomous System Number) unique to each instance. Make sure the ASNs are different for each NSX instance to avoid conflicts. Use ASN from 65XXX.

   Im my case I will use:

   • NSX Instance 1: ASN 65051
   • NSX Instance 2: ASN 65052

4. Set BGP Neighbor Configuration: Under the BGP configuration, you need to specify the neighbor IP address (the IP address of the remote (second) NSX Edge), as well as the remote ASN of the opposite NSX EDGE.

   In my LAB it is:

   • NSX Instance 1:
     • Neighbor IP: 172.17.5.2
     • Remote ASN: 65052
   • NSX Instance 2:
     • Neighbor IP: 172.17.5.1
     • Remote ASN: 65051

5. Configure Networks to Advertise: Decide which networks each NSX Edge will advertise to the other NSX instance. We can do rout-map filtering as well, if required. It allows to control exchanging the routes between EDGEs.

6. Enable BGP: Ensure you enable the BGP session on both NSX Edges. Check the "Enable BGP" box and save the configurations.

7. Verify BGP Session: Once the BGP session is established, verify the session status from the NSX Edge interface:

   • Go to System > Routing > BGP.
   • Ensure the BGP session is Established and that the advertised routes are visible under the Routing Table.

8. Monitor and Troubleshoot:

   • You can use tools like show bgp summary or show bgp neighbor from the NSX CLI for troubleshooting.
   • If the session does not come up, verify IP reachability between the two NSX Edges and check for any misconfigurations in ASNs or neighbor IPs.
   • In my experince it is easy task allow dynamically exchange routing information and automatically adjust paths based on network changes.

Always practice on the LAB before implementing in production.