I sometimes hear or read complaints about the Nexus 5000 + Nexus 2000 fabric extender architecture that I want to take a minute to address. This should be short and sweet, a blogging concept that is foreign to me if you follow my work.
The typical complaints about this architecture from network engineers are as follows. These are direct quotes from a recent conversation:
“Unfortunately, Nexus 2000 is just a fabric extender and can ONLY be attached to Nexus 5000…”
“I haven’t figured out yet what’s the advantage of having this design (nexus 2000 -> nexus 5000) other than the “old” one (catalyst 4948 -> nexus 7000/cisco 6500).”
“The Nexus 2000 does no local switching so if you have any east-west traffic between ports on the same switch you’ll be better served by a more traditional access switch”
The Nexus 2000->5000 design does require looking at things a bit differently than you have in the past. Data Center architecture is changing fast due to the rapid onset of Data Center virtualization. Server & Storage administrators have been struggling with this change as well, this isn’t something unique to the Network.
There is a tendency to view the Nexus 2000 as a switch. And understandably so because it’s packaged like a switch, looks like a switch, and installs in the rack like a switch. Because of this perception it’s easy to subject it to the typical switch design criteria. But in doing so you begin an exercise that leads to more frustration than clarity because you are applying old thinking to new technology.
It makes more sense to view the Nexus 2000 as a linecard that has been pulled out of a switch, packaged up in sheet metal, and the backplane ports connecting to the supervisor engine changed to SFP+ ports. You now have a linecard that connects to its supervisor engine with cables.
Why is that significant? Because it reduces the complexity (and therefore total cost of ownership) of adopting a Data Center virtualization architecture.
For example, (10) Nexus 2000′s are managed no differently than (10) linecards. I think we can all agree that a linecard requires a lot less management than a switch.
It also allows the Data Center to grow into larger L2 domains required by virtualization by minimizing the # of L2 nodes, because the Nexus 2000 links to data center with L1, versus L2.
Business leaders are hearing a lot about cloud computing these days, and the cost advantages it promises to the business. Yet there is a valid concern with data privacy and security that comes with public cloud computing. If internal IT can transform their data centers into a private cloud, or at least drastically improve the operational efficiency and total cost of ownership of their own data centers … the wholesale outsourcing of the data center applications to the public cloud become less attractive to the business leaders.
In other words, wake up and smell the cloud. Your career may depend on it.