Summary for the impatient
If your solution to a complex problem makes things simpler for you by making it harder for somebody else, you’re probably doing it wrong. I’m looking at you, VXLAN.
A few days ago I watched a brilliant presentation by Scott Shenker – The Future of Networking, and the Past of Protocols (YouTube link). The theme of developing useful abstractions to bring the essence to the surface while de-emphasizing the non-essential complexity really resonated with me, as it has been my unofficial mission for years.
The topic of the talk is, of course, the SDN. Which brings us to one of the more notable technologies getting a lot of air time is VXLAN; what with gaining support from everybody and their mom (including, as of this week, the OVS).
You can call me whatever you like, but VXLAN is making me uncomfortable. You see, to function efficiently, it needs IP multicast configured in the underlying transport network. I know, there are many organisations out there familiar with multicast, having had to implement it for things like Music On Hold, if nothing else. However I would hazard a guess that there are more organisations where there is no multicast currently, and as far as I know, correctly designing, configuring and operating multicast networks is anything but simple.
I feel that by relying on IP multicast, VXLAN is creating additional pressure and not making things simpler for all – just for those who use virtualised networking services. The way VXLAN is going about the problem, in my opinion, is not by extracting simplicity, but by shifting complexity. For an example of a better way, look at the QFabric – simple on the surface; complexity tucked away, not dumped into somebody else’s lap.
The argument, of course, would be that VXLAN is “open”, while QFabric is “proprietary”, but I think it is worth remembering that in the early stages of a new round of evolution tighter coupled solutions often provide better user experience; and at the end of the day it is all about the user.
Will it stop wide VXLAN adoption? Don’t think so; however it does have me looking somewhere else.