Exam 2V0-11.24 topic 1 question 75 discussion

In NSX-T, the Tunnel Endpoint (TEP) interfaces on ESXi hosts are responsible for encapsulating and decapsulating overlay traffic (Geneve encapsulation). If the tunnel status is showing as "down", it usually means that TEP-to-TEP communication is failing. One common cause is that firewalls or network devices between the hosts are blocking overlay traffic, which typically uses UDP port 6081 for Geneve encapsulated packets.

In NSX-T, ESXi hosts communicate through Tunnel Endpoints (TEPs) using Geneve encapsulation. If the Tunnel status is "Down", it means the overlay communication between ESXi hosts is failing. The most common cause of this issue is that overlay traffic (UDP 6081) is being blocked by a firewall at the gateway or upstream network device. Why "Overlay Traffic Blocked by Firewall" is the Correct Answer? NSX-T uses UDP port 6081 for Geneve encapsulation to create overlay tunnels between ESXi hosts and Edge Transport Nodes. If a firewall blocks UDP 6081, TEPs cannot establish communication, causing tunnels to show "Down" in NSX Manager. Solution: Ensure that UDP 6081 is allowed between all transport nodes (ESXi hosts, Edge Nodes, and NSX-T Managers).