Attention: overlay tunnel construction ahead

A while ago I wrote a few articles describing the various tunnel protocols used for network virtualization between vSwitches on servers, and between vSwitches and physical network gateways. These are the mechanisms that construct overlay networks on top of a physical network. VMWare uses STT as the tunneling mechanism between vSwitches on servers and VXLAN […]

Stateless Transport Tunneling (STT) meets the Network

Last week I walked through the packet formats for VXLAN and NVGRE specifically focused on ways by which the overlay packets provide information to the physical network that help the physical network. Some of the initial extreme thoughts that the overlay and physical network can and should be completely ignorant of each other have softened […]

Aggregation is Good. Aggregation is Bad.

For as long as I remember networking has struggled with the balance between aggregated and individual traffic flows. Following the abilities of the technology components we use, we have been forced to aggregate, only to be allowed to de-aggregate or skip aggregation when technology caught up or surpassed the needs of today. The vast majority […]

About underlays

Greg Ferro (@etherealmind) wrote an article a few weeks ago outlining his thoughts on how integrated physical and overlay networks would not be successful. I would like to expand a bit on some of the points Greg raises, and give (a piece of) our view on this topic. First I want to touch on terminology. […]