NSX Edge Uplink 'Inactive' After Changing BGP Peer IP Address and Max Hops

Products

• VMware NSX

Issue/Introduction

When attempting to change the BGP Neighbor IP address and max hops in NSX, the Edge uplink goes into 'Inactive' state and does not pass traffic. 

In the T0 SR vrf: 

• 'get route bgp' or 'get route <bgp_neighbor_IP>' shows Inactive, rather than the Edge uplink. 

• 'get bgp neighbor summary' - BGP neighborship is established.

• All traffic sent to this neighbor is dropped.

Environment

VMware NSX

Cause

This is the result of a software defect, that causes it to see the next hop as inactive, causing the uplink to be put in the 'Inactive' state. 

Resolution

This issue will be resolved in a future version of NSX.

Workaround: 

• Change the "Max Hop Limit" of the other BGP neighbors to match the new neighbor. 
• Explicitly select the "Source Addresses" for the other BGP neighbors. 

Setting the "Max Hop Limit" will cause a BGP flap. For this reason, the recommendation is to make these changes during a maintenance window.

Additional Information

If you are contacting Broadcom support about this issue, please provide the following:

• State of the BGP connection reported on peer device
• Are you able to ping the peer device from the T0 SR
• How long as the session reported down/has this ever worked?
• BGP configuration on peer device
• State of the physical network
• Log bundles of NSX Edge nodes

Handling Log Bundles for offline review with Broadcom support

• Collect Support Bundles for Troubleshooting NSX-T
• Uploading files to cases on the Broadcom Support Portal
• Creating and managing Broadcom support cases