I’ve been working in the lab again, and I attempted to log in to one of my switches (IP addresses have been changed to protect the innocent):
$ ssh admin@10.10.18.73
Warning: Permanently added '10.10.18.73' (RSA) to the list of known hosts.
admin@10.10.18.73's password:
Permission denied, please try again.
Huh? I checked caps lock, and even logged into another switch to make sure I wasn’t making any mistakes typing my password of “cisco123”. (So kill me, it’s a lab router.)
Nothing seemed to be working, so I logged into the router successfully via terminal server, and ran debug aaa authentication and debug ip ssh. Neither provided any insight. I did a show run | sec line and saw this:
line vty 0 4
exec-timeout 0 0
privilege level 15
logging synchronous
login local
transport input ssh
line vty 5 15
login
“OK”, I thought, “what if I’m hitting VTY5 and not getting local login?” I replicated the config and now saw this:
line vty 5 15
exec-timeout 0 0
privilege level 15
logging synchronous
login local
transport input ssh
I was able to get in, just fine, and on doing a “show line” I could see that I had indeed tied up a bunch of my lines with dead SSH sessions. That’s what I get for using exec-timeout 0 0.
It wasn’t exactly the troubleshooting session of the century, but every engineer knows that wonderful feeling of victory and that warm subsequent thought of “I know my stuff.” (Of course, knowing my stuff is what got my lines tied up in the first place.)
I’ve written in the past about the war on expertise. There is a widespread belief among industry “analysts”, MBA executive types, and even some network engineers, that AI will just do our jobs for us, at some point. The arcane knowledge we specialize in, whether routing protocol nuances or Cisco’s ancient “line vty” syntax, will soon no longer be required.
Of course, we’ve been down this path before. Over and over (and over and over!) again in my career, I’ve heard of the death of network engineering. So-called controllers, intent-based networking, automation, scripting, and now AI will remove the need for our specific expertise. Don’t get your Cisco certification, get your Nvidia certification instead!
AI certainly seems to be the most credible threat I’ve seen. When it’s not busy calling itself “MechaHitler” and threatening to exterminate an entire race, AI is pretty good at destroying human jobs. Entire professions are being decimated by ChatGPT, obliterated by Gemini. Programmers are definitely at risk. I use Claude to build software without having to write a line of code. Sometimes it actually works.
Leaving aside the question of “will it?”, we’re left with the question of “why should we let it?” I started configuring Cisco routers in 2000. 25 years of dealing with these machines means that I feel a sense of comfort logging into an IOS-type command prompt. I feel at home in a way I never did with Junos (even with a JNCIE). I know this box and its quirks. What it does well, and what it doesn’t. I know where the CLI makes no sense (a lot of places, really), and where I need to use workarounds. There is a joy among humans in acquiring hard-won expertise.
The carpenter who calculates angles in his head, the electrician who sorts through tangles of wires without thinking about it… The pilot who hand-flies the plane even with an autopilot, the surgeon who can locate that appendix in what looks to everyone else like a sea of red meat. Human beings thrive on learning and mastering.
AI has the potential to take that away. I feel like there is a legitimate threat to humanity when we crush the human spirit with technology.
Meanwhile, like everyone else, I’m playing with AI and MCP servers, trying to stay relevant so I can still have a career. I see AI the way I saw automation and scripting. A tool, not a replacement.
I may be wrong, though. Maybe our careers will be decimated just like those of graphic designers. I’m not sure what I’ll do in that case. I can juggle, maybe join the circus? At least until the robot jugglers replace us too.