How To Build a 100,000-Port Ethernet Switch

BobB-nw writes "University of California at San Diego researchers Tuesday are presenting a paper (PDF) describing software that they say could make data center networks massively scalable. The researchers say their PortLand software will enable Layer 2 data center network fabrics scalable to 100,000 ports and beyond; they have a prototype running at the school's Department of Computer Science and Engineering's Jacobs School of Engineering. 'With PortLand, we came up with a set of algorithms and protocols that combine the best of layer 2 and layer 3 network fabrics,' said Amin Vahdat, a computer science professor at UC San Diego. 'Today, the largest data centers contain over 100,000 servers. Ideally, we would like to have the flexibility to run any application on any server while minimizing the amount of required network configuration and state... We are working toward a network that administrators can think of as one massive 100,000-port switch seamlessly serving over one million virtual endpoints.'"

Comments

It's all about address management

[Animats]

The paper is about adding a layer of addressing so that IP and Ethernet addresses can be moved from one machine to another as instances of virtual machines are migrated around. It's not about the problems of physically building a very large switch. The switch components are mostly stock items.

Re:You still need isolation

[amorsen]

What do you do about broadcast storms?

In the paper they detail how they handle ARP. All other broadcasts you can get away with dropping these days; use multicast instead. (Yes, that will break NETBIOS broadcast name lookups. So sad.)

How do you prevent some clown from anywhere in that 100,000 machine cloud from poaching another machine's IP address (either maliciously or by an accidental typo)?

That is a solved problem if you use decent switches. You can apply pretty much any policy you like.