Simple definition
A VXLAN Tunnel Endpoint encapsulates and decapsulates Ethernet frames in UDP to connect virtual network segments.
Purpose and use
A VTEP, VXLAN Tunnel Endpoint, encapsulates and decapsulates traffic between an Ethernet segment and a VXLAN network.
How does it work?
The VXLAN header identifies the segment with a VNI and carries frames over UDP, using standard destination port 4789.
Example and verification
For lost connectivity between hosts on an extended segment, check VNIs, IP reachability between VTEPs and transport-network MTU.
Points to watch
Matching VNIs are insufficient if mapping tables or the control plane are wrong. VXLAN alone does not encrypt frame contents.
In short
A VTEP connects overlay and underlay networking; both layers must operate correctly to provide connectivity.