Finally got around to hardening my Zero after reading up on what actualy runs in the background on these machines. The wifi setup tool that comes bundled on it sits there listening all the time, even when you never touch it. Since my printer sits on the same network as everything else in the house, that bugged me. SSH'd in, stopped the service and made sure it won't come back on its own. Whole thing took about two minutes. Then I regenerated the SSH keys too, because who knows how many units shipped with identical ones. When I reconnected afterward my terminal complained the key had changed, which freaked me out for a second til I remembered that's exactly what shold happen. Cleared the old entry from my known hosts file and reconnecting worked fine. One thing to keep in mind: a firmware update can silently turn that wifi service back on, so it's worth rechecking after any update. I've added it to my little post-update routine now, right next to checking belt tension.
Spent last night locking down my Zero and feel much better about it now
Nov 02, 2026
Last reply: 2 days ago
3 Replies
Did the same round of cleanup on my SV08 a couple months back and it was weirdly satisfying. I didn't go as far as killing the wifi service though, since I use the app to check prints from work sometimes. Instead I moved the printer onto my router's guest network, which keeps it away from my NAS and the family laptops. Took some fiddling with the router settings but now it can only talk outward, not sideways into my stuff.
The SSH key thing I did do, and yes, that first reconnect warning after regenerating gives you a jolt even when you know it's coming. Same fix on my end, cleared the old line from known hosts and it connected fine after that.
Your note about updates undoing things is a good one. Mine came back enabled after an update around March and I only noticed because the printer showed up in a network scan I ran for unrelated reasons. Now I just glance at the running services after every flash, takes thirty seconds. I keep a little text file on my desktop with the post-update checklist, kind of dorky but it has saved me twice now.
I took the lazy route and just never connected mine to the network at all. My SV07 sits in the garage, gets its files off a USB stick, and the only remote monitoring I get is walking out there with my coffee. Sounds primitive after reading you two talk about service lists and guest networks, but it solved the whole worry in one go. My router's device list stays clean and I sleep fine.
The tradeoff is I can't check prints from the couch like my buddy can with his setup. Once or twice I've wished for it when a long job was running overnight, but honestly if a print fails at 2am, knowing about it at 6am costs me the same filament either way.
One thing I did pick up the hard way: those USB sticks get shuffled around the house more than you'd think, and mine picked somthing odd off the kids' laptop at one point. Now the stick that goes in the printer lives in a drawer next to it and never travels. Small habit, but it keeps the offline setup actually offline.
Gotta push back on the guest network bit though. Isolation on those is not a given, it depends entirely on how the router implements it and plenty of cheap ones just put guests on the same subnet with a diferent name. I believed mine was isolated for a year until I pinged my laptop from the printer's side and got a reply. Also 'talks outward only' still means it phones home whenever it feels like it, which is half the problem you were trying to dodge. Check the actual settings for client isolation and AP isolation, don't just trust the word guest.
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