BGP sends a route to an eBGP peer with peer's own address

Products

• VMware NSX Networking

Issue/Introduction

Symptoms:

• ESG advertises BGP routes to neighbor with next-hop as neighbor address, instead of local address when default originate is enabled on the neighboring router.

show_ip_bgp
  > 0.0.0.0/0          3.3.3.3      1     100      60   64523 i

 

• eBGP neighborship between ESG and neighbor.
• Routes affected are the ones learnt from an iBGP peer after the iBGP connection is flapped. It can cause traffic loss since next-hop for routes is incorrect.
• In BGP advertised routes command, we can see next-hop for routes is the neighbor IP instead of local IP.

show ip bgp neighbors 3.3.3.3 advertised-routes
[..]
1.1.1.0/24 3.3.3.3  0 0 ?
2.2.2.0/24 3.3.3.3  0 0 ?
[..]

 

• If we check the routes on the neighbor, the next-hop will be incorrect.

Resolution

This issue is resolved in NSX-v 6.4.11 or later.

Workaround:
You can workaround this issue by carrying out any of the following:

1. Restart BGP process. This will make the Routing Table Manager re-compute and re-advertise the correct routes.
2. Reboot ESG appliance

Additional Information

https://docs.vmware.com/en/VMware-NSX-Data-Center-for-vSphere/6.4/rn/VMware-NSX-Data-Center-for-vSphere-6411-Release-Notes.html

 

Fixed Issue 2708365: ESG advertises BGP routes to neighbor with next-hop as neighbor address, instead of local address when neighbor has default originate enabled.