The Twilight of the Age of Conf T
September 6, 2013 5 Comments
That sums up the networking world as it exists today. Conf T.
On Cisco gear, that’s the command you type to go into configuration mode, and also a lot of gear that isn’t Cisco. It’s so ingrained in our muscle memory it’s probably the quickest thing any network engineer can type.
On Nexus gear, which runs NX-OS, you don’t need to type the “t” in “conf t”. Typing “conf” will get you into configuration mode, no “T” is required. Same for most other CLIs that employ the “industry standard” CLI that everyone (including Cisco) appropriated.
Yet most of us have it so ingrained in our muscle memory we can’t type “conf” without throwing the “t” at the end. (I had to edit that sentence just to get the “t” out of the first “conf”…. dammit!)
But is that age ending?
VMware released NSX, other companies are releasing their versions of SDN, SDDC, and.. whatever. These are networks that more and more will be controlled not by the manually punching out a CLI, but rather GUI and/or APIs.
We’ve configured networks for the past — what, 20 years — by starting out with “conf t”. And we’ve certainly heard more than one prediction of its demise that turned out to be a flash in the pan. However…
This certainly feels like it could be the beginning of the end of the conf t age. How does something this ubiquitous end?
Gradually, then all of a sudden.
The Data Center Overlords 
Can’t see why a CLI is inferior to a GUI. How can that Unix/Linux are strong configured using CLI?
You’re right…a CLI isn’t inferior to a GUI, but what the CLI is going up against isn’t a GUI, it’s automation orchestrated by the person who used to log into the CLI.
The big wins are speed of change and convergence, repeatability, and manageability of the configuration.
It’s the same reason that the best practice on servers is to use configuration management. The software that enforces the configuration becomes its own documentation in a way.
When you change from entering commands to do things to writing software to do things, your workflow can include much better practices like version control, integration testing, and so on.
Even vmware itself PowerCLI. While there may be some things more easily done through a GUI there are also things easier done on a CLI. I don’t see the CLI completely going away – PowerShell and PowerCLI are examples of that.
I could see the CLI maybe not becoming the PRIMARY method of configuration work, but I think it will still exist.
I think my biggest issues with GUIs are that often it is harder to get all the options in a GUI pull-down that you can get on a CLI option (the above comment on Unix/Linux shows that – look at all the options on a command like find or grep – just hard to fit that many in a GUI). The other is that when verifying things look good, on a GUI you can miss things if you are not on the right “screen” wheras something like a running config it is easier to see everything. Now an argument could be made that in today’s networking works you still have to be on the correct device to see an issue which is true, but if we could combine the SDxx stuff with a good CLI and have something like a running config for the whole network that would be pretty cool.
I don’t buy a GUI is better then a CLI and doubt the CLI will go away completely just like Linux/Unix have nice GUIs, but the CLI hasn’t been removed either.
I just pulled up the data sheet on Dell’s Switch Gateway for VMWARE NSX and one line in that data sheet is “CLI for virtual and physical networks” and in more detail “AFM includes Command Line Interface (CLI) specifically developed for VMware’s vSphere Distributed Switch (VDS). The CLI provides network administrators a familiar, consistent means for visibility into and management of both virtual and physical networks.”
IMO it will go down just like server visualization 10 years ago, slowly but gradually. You will have your nitch markets like ISPs and such that will still use dedicated hardware.
This is also all hinged on VMware and others providing a solid solution that can integrate well.
I for one think the next 10+ years is going to be a awesome time in the networking field!