Ivan Pepelnjak joins Steinn and Urs to talk about netlab, why multi-vendor ACLs are a hellscape, and what AI can and cannot do with network configuration.
Ivan is a CCIE Emeritus, the author of more Cisco Press books than most of us have read, the voice behind ipSpace.net, and the creator of netlab — an open source tool that builds and configures virtual labs across roughly twenty platforms. He describes it himself as an "intent based digital twin lifecycle management system", then immediately admits that's a bullshit bingo winner if you have the right card.
The conversation digs into why LLMs write decent Python and bad router configs (vendor CLIs are almost identical but not quite, which is the worst possible training data), the ChatGPT doom loop Ivan hit trying to configure EVPN on Nokia SR OS, and the endless device quirks behind multi-vendor abstraction — Juniper loopbacks, Nokia prefix lengths, and one vendor with roughly 400 keywords you are not allowed to use as a VLAN name.
Plus: why every layer 3 switch is really a bridge in disguise, why ACLs are containable and QoS never will be, what a real CCIE engagement looks like when you have twenty years of customer mistakes and exactly one command to fix them, and Ivan's controversial opinion on conferences.
What we cover
What netlab actually is, and the five years behind it
Whether netlab is a crutch for beginners
Splitting a lab across multiple servers with automatic VXLAN tunnels
Netlab vs containerlab and Kubernetes-based labs
Why AI generates good Python and bad router configs
The ChatGPT doom loop on Nokia SR OS EVPN
Cloning production into a lab: control plane works, data plane is a lottery
ACL support in netlab, Cartesian products and resequencing
AI code review vs AI code — technically correct and five times too long
Vibe coders, 1982 edition, on a ZX Spectrum
Leaky abstractions and worst common denominators
Device quirks: Juniper, Nokia, Cisco, and 400 forbidden VLAN names on EXOS
Why every layer 3 switch is a bridge with a router attached
ACLs are containable. QoS is not.
BGP labs designed like gym machines
Why CCIE lab scenarios are so insane — and why they're accurate
The power of saying no, and the customer who said thank you
Controversial opinion: the hallway track is the only track
Podden och tillhörande omslagsbild på den här sidan tillhör
Steinn Örvar. Innehållet i podden är skapat av Steinn Örvar och inte av,
eller tillsammans med, Poddtoppen.
