Encapsulation of layer 2 frames in UDP on port 4789. Gateway Load Balancer chains NVAs with it, and Azure Extended Network uses it to carry a stretched subnet between its pair of appliances.
Also called Virtual Extensible LAN.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains VXLAN in context, with comparison tables and the common traps.
Terms in this definition
- L2
Layer 2 of the OSI model, the data link layer of frames, VLANs and MACs. An NSX segment is one broadcast domain at this layer.
- UDP
A transport protocol that sends data without establishing a connection.
- Gateway Load Balancer
A load balancer SKU that inserts transparent third-party NVAs into the path of a Standard Load Balancer frontend, using VXLAN to chain them.
- Azure Extended Network
Windows Admin Center feature letting migrated VMs keep their IP addresses by stretching an on-premises subnet into Azure; two appliance VMs carry a VXLAN tunnel between them, and up to 250 addresses can be extended.
- Subnet
A segment of a VNet's address space from which resources receive private IPs. Azure holds back five addresses per subnet (the first four and the last), leaving 251 usable in a /24 and three in a /29, the smallest IPv4 subnet.