On Wed, Dec 17, 2025, 19:51 Dan Mahoney via NANOG <nanog@lists.nanog.org> wrote:
Hey there folks.
Dayjob has historically used USB TTY pods attached to real BSD machines to talk to our cisco consoles, with the amazing benefit that with a program like Vixie's rtty (or conserver) you can also capture the output of those consoles in real-time, and perhaps use that data to identify a connected device.
As a bonus, because the rackmount devices have real DE-9's on them, it means they work with any kind of cable you get (not just your standard rj45 cisco rollover like you might get with a Cyclades thing -- and you don't have to come up with the weird-ass mappings for rj45-serial like you might need like our ME4012 NAS (the serial cable is a stereo plug), our smart power strips (it's either a stereo plug, or an rj12), or something like an older brocade switch (it's a DE9, but it's friggin ODD, and I think it may also be the wrong gender).
It also means, since you're running a real OS, you have patches as long as the OS is supported (so you're not stuck with "gee it only speaks rsa1024"), versus some EOL appliance. But it's also 2u, and since we're recently buying a lot of Dell hardware, that's Super Overkill for a dell, so I'm evaluating maybe just going "Appliance".
If we stick with an existing unix box for this, I'd want something with proper IPMI/OOB (so Rpi is out) but maybe the dumbest, shallowest-depth atom64 supermicro you can find, in the event you need to do a reinstall or catch a hung system.
Are there things that other folks are using that are "easy" to work with that you've found to have Long firmware lives, decent warranties and low hassle? Does anything these days actually have DE9s on it?
-Dan
(You may have also seen my note earlier about the Cisco ASR920, which has RS232 pins in a USB-A header. No, not via a PL2032 chip inside the host that provides a virtual serial...direct txd/rxd/gnd/cts etc, on the USB pins. I've seen things you people would't believe)
Dan (et. al.) - Hear me out. Unconventional and might raise some eyebrows, but way cheaper, modular (no more "I used to have"s, "can't find them anymore"s, etc.), and if it works for you it works. 1. Serial "concentrator"/"multiplexer": miniPC, something like https://www.amazon.com/dp/B0DGGFR68Y Chuck Linux/BSD on it, add something like one (or more) of the following: https://www.conserver.com/ https://github.com/xcat2/goconserver https://github.com/wd5gnr/SerialMux https://eluaproject.net/doc/master/en_sermux.html https://github.com/danielinux/ttybus Some (esp. the N95 chip ones, but the N100s tend to be a bit more power efficient) can run fine with completely passive cooling. 2. Add in a *dedicated power* (no power-from-host-device) large-number-of-ports USB hub. Something like: https://www.amazon.com/dp/B07JM9ZFFV plus whatever connector adapters you need. 3. For OOB mgmt on the miniPC, IP-KVM. These two are the current hotness and are dirt cheap. https://blog.hardill.me.uk/2025/03/30/nanokvm-and-jetkvm-ip-kvms/ No power control like you would with a BMC or DRAC, but you can just bounce from the PDU or whatever if it gets that drastic. YMMV and it's not for everyone, but again- if it works for you, it works.