VXLAN for Linux
Just published a Linux kernel implementation of VXLAN for possible inclusion in 3.7 kernel (patches).For those unfamiliar with VXLAN, here are some common questions.
Q: What is VXLAN?
It is a standard protocol to transfer layer 2 Ethernet packets over UDP.Q: What is the VXLAN protocol?
The standard is under development, the current draft RFC is at version 2.Q: Why do we need yet another tunnel protocol? Why not just use GRE?
Existing tunnel protocols depend on properties of the backbone which may not be available. Generic Routing Encapsulation works by tunneling over IP and maybe blocked at routers by firewalls that only accept TCP and UDP.Q: Does Openvswitch already do VXLAN?
The development version of Openvswitch does have VXLAN support, but OVS is fundamentally different than normal Linux networking. Many people may not want to take the jump into OVS. There are many cases where existing Linux networking technologies are easier to configure and use.Q: What could VXLAN in Linux be used for?
It could be used to terminate VXLAN in Linux router, or link Linux bridges across hypervisors, or talk to legacy expensive virtualization products.Q: Why is VXLAN cool?
Read the blogosphere, here are some good starting points- Ivan Pepelnjak: VXLAN and OTV I've been suckered
- Digging Deeper into VXLAN, Part 1
- Examining VXLAN
- NVGRE vs VXLAN on Packetpushers podcast
