I have created a VLAN segment in NSX and a T-0 gateway. I added the created VLAN segment as the Tier-0 interface. Then, I created an overlay segment and connected it to the T-0 gateway.

Everything was fine until I connected the Overlay segment to one of the virtual machines, causing the Edge node and the ESXi host to go down.

I checked the VTEP between the ESXi hosts and the edge node, and they are responding with an MTU of 1700.

I'm using 192.168.8.0/24 for the management, which the ESXi hosts, NSX appliance, vCetner, and Edge node management IP are in this range.
And 192.168.10.9/24 for the VTEP IP range.

Here are the error messages that show in the NSX:

TEP Health, Faulty TEP
Description :
TEP:vmk10 of VDS:VDS at Transport node:2e7e8310-aabb-4c9e-aec1-9f37ed1f9fa8. Overlay workloads using this TEP will face network outage.

Recommended Action
1. Check if TEP has valid IP or any other underlay connectivity issues. 2. Enable TEP HA to failover workloads to other healthy TEPs.

Infrastructure Communication, Edge Tunnels Down

Description:
The overall tunnel status of Edge node 31829895-3a35-432f-a2d3-0b3d24469dd6 is down.

Recommended Action:
Invoke the NSX CLI command `get tunnel-ports` to get all tunnel ports, then check each tunnel's stats by invoking NSX CLI command `get tunnel-port <UUID> stats` to check if there are any drops. Also check /var/log/syslog if there are tunnel related errors.

High Availability, Tier0 Gateway Failover
Description:
The tier0 gateway 94bd643e-a463-452c-9c66-b734a6c31623 failover from Active to Down, service-router 3b7b34f6-ebee-4dd6-afc4-ae777f7d4fd3

Recommended Action:
Invoke the NSX CLI command `get logical-router <service_router_id>` to identify the tier0 service-router vrf ID. Switch to the vrf context by invoking `vrf <vrf-id>` then invoke `get high-availability status` to determine the service that is down.