Early on in IT the only one way to manage a system, be it a MUX, Controller, Server or Modem was via the Command Line Interface (CLI). Windows and MAC’s were our first real introduction into GUI (Graphical User Interface) based management and for some tasks it was a lot easier to deal with. The younger generation has come to expect GUI systems and probably find CLI cumbersome and archaic, but the older generation, the generation that grew up with Unix, Cisco IOS and a number of other systems that don’t exist anymore, will probably tell you that CLI is the only way to go.
I sit somewhere in the middle. While I recognize the flexibility and speed that a CLI can give you, I sometimes yearn for the colours and charts that can make quick work of a task that requires a number of memorized commands with outputs that are sometimes hard to read. I have been configuring and Managing Cisco Routers and Switches for well over 15 years, so when it comes to Cisco IOS, Command Line is the obvious choice. It does require a fair amount of memory work but when you do it day in and day out it becomes second nature. Cisco attempted a few GUI systems for the old PIX and now ASA Firewalls, but I can tell you, as crazy as a complex Firewall configuration can get, the GUI system is that much more complex. A poorly written GUI can be even more confusing than CLI.
I recently worked with a customer that, for the most part, was not comfortable with CLI, and since we were looking at installing a number of Cisco switches in their network, I took the opportunity to give the customer a really quick Cisco CLI overview. As I said, Cisco CLI is second nature to me, but in listening to the reaction of the customer I realized how intuitive Cisco’s CLI really is.
Back before Juniper bought Netscreen, we were big fans of Netscreen’s ScreenOS. Not exactly like Cisco, but very intuitive. Juniper bought Netscreen and for a while it was status quo, but then Juniper decided to push the SRX series, based on the JunOS software. Now, I can use JunOS, but is it intuitive? Is it easy to use? NO and NO… I know there are a lot of JunOS fans out there and I am by no means knocking the product or its capabilities, just pointing out that in my opinion the interface for the CLI is not up to snuff.
The CLI is harder to learn, requires a certain amount of memorization and probably requires you to get a better understanding of the technology and what it is doing. Sometimes you can get something working via a GUI just be clicking around until it works. Certainly not recommended, but I’ve see it in action. Whatever your preference, don’t ignore the CLI. In most cases what you do in the GUI gets translated into commands via CLI behind the scenes. If you are unclear how to use the CLI on any particular system, I recommend using the GUI to set it up, then going back to the CLI to see what those GUI clicks did to the configuration in the CLI.