In this week’s episode of Engineers Unplugged, storage industry luminaries Chad Sakac (@sakacc) of EMC and Vaughn Stewart (@vstewed) of NetApp discuss the concept of Stretch Clustering, a topic they’ve been covering at tech events for awhile now. Check out their discussion here:
Welcome to Engineers Unplugged, where technologists talk to each other the way they know best, with a whiteboard. The rules are simple:
Episodes will publish weekly (or as close to it as we can manage)
Submit ideas for episodes or volunteer to appear by Tweeting to @CommsNinja
Practice drawing unicorns
Collaborative Storage Unicorn, courtesy of Chad Sakac and Vaughn Stewart
For more information on stretch clustering and all storage topics, be sure to check out Chad’s blog and Vaughn’s blog. Questions, comments, thoughts? Post them here or join the conversation with @CiscoDC on Twitter!
So, lets dig into LISP Routing a little more. If you have not done so, I would recommend you read my first post, since I am not going to review the concepts here. In this post, I am going to break things down into three steps: 1) how packets are forwarded (i.e. the data plane operation), 2) how mapping information is propagated (i.e. control plane operation), and 3) how we internetwork with non-LISP locations.
For starters, lets head into the weeds and take a look at the LISP header format. In the last post, I mentioned there is some flexibility in how handles IP addressing. The two examples below show a couple of scenarios: pure IPv4 and a IPv4/IPv6 hybrid:
I am going to spend the next couple of posts digging through one of the more interesting new technologies we are working on: a standard called Locator/ID Separation Protocol (or LISP). Why should you care—well if you are looking at deploying clouds, supporting mobility of end-points or VMs or are managing a routing architecture or any meaningful size or complexity, I think it will be worth your while to check out LISP.
LISP is a new approach to routing that is designed to address the changes in how we are using our networks. Lets explore LISP through the lens of one of the biggest challenges facing network architects today: properly tackling mobility, whether its mobile endpoints like smartphones, tablets or squirrels or the mobile workloads that are at the heart of server virtualization and cloud computing. While mobility this is probably the “sexiest” use case right now, there are a number of other use cases, like routing architecture scalability and IPv6 migration, which, while less alluring to all but the biggest networking nerds, are no less important.
The networking industry has recently developed a renewed interest in virtual overlays, often wrapped in an “SDN as the controller” context. Amidst the promise, the hope and the hype, the following questions present themselves:
What exactly is an overlay?
What distinguishes an overlay from a VPN?
How decoupled can an overlay be from the underlay network and what are the tradeoffs?
What are the advantages of overlays and will they emerge as the new networking world order? Read More »
It is amazing how the data centre world has changed in the last few years. A Data Centre used to be a collection of network elements to interconnect static servers (and their associated storage), with traffic patterns that were highly predictable and mostly north-south. Cloud and virtualization have changed all of this: a data centre is now a collection of compute and storage resources which can be securely sliced up into virtual networks and placed anywhere according to real time needs, interconnected by a fabric. The virtualization of servers, network services such as firewalls and load balancers, and even network devices such as switches and routers, has created a very dynamic landscape in terms of how fast you could configure a virtual network, in a way where location shouldn’t really matter, and where compute and storage resources can be added on the fly, based on demand. Multi-tenant Data Centres, such as the one to deploy Virtual Private Clouds, need to support 10000’s of these virtual networks. And every one of these virtual networks needs a lot of different service instances to stitch together the virtual network across virtual servers, virtual switches, virtual firewalls, virtual load-balancers, and virtual routers. Traffic patterns have shifted to East-West, because of the new applications which spread processing across many hosts, and because of the ‘location freedom’ that virtualization allows. Network infrastructure needs to be cost-effective to handle all this traffic, while the increased lookup-table size caused by the any to any traffic patterns often led to increased cost. Read More »