Re: What are folks using for serial consoles these days?

[Owen DeLong via NANOG <nanog () lists nanog org>]

Well, if you’re determined to have IPMI, you’re asking for a lot of extra expense with minimal benefit.

OTOH, if you power it via PoE or a controllable outlet accessible via your OOB network, I find that a NanoPi R6S or 
R.Pi with a USB hub and a bunch of FTDI serial dongles works great.

I highly recommend the following udev rule, however, to avoid unpleasant naming surprises on the USB ports:
SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001",SYMLINK+="tty.FTDI.%E{ID_SERIAL_SHORT}"


This creates an additional /dev/ symlink named tty.FTDI.<Serial>, so for example:

root@asilomar:/var/log# ls -al /dev/tty* | grep 188,
crw-rw---- 1 root dialout 188,  0 Dec 22 04:06 /dev/ttyUSB0
crw-rw---- 1 root dialout 188,  1 Dec 22 04:06 /dev/ttyUSB1
crw-rw---- 1 root dialout 188,  2 Dec 22 04:06 /dev/ttyUSB2
crw-rw---- 1 root dialout 188,  3 Dec 22 04:06 /dev/ttyUSB3
crw-rw---- 1 root dialout 188,  4 Dec 22 04:06 /dev/ttyUSB4
crw-rw---- 1 root dialout 188,  5 Dec 22 04:06 /dev/ttyUSB5
root@asilomar:/var/log# ls -al /dev/tty.FTDI*
lrwxrwxrwx 1 root root 7 Dec 22 04:06 /dev/tty.FTDI.A99AGU55 -> ttyUSB5
lrwxrwxrwx 1 root root 7 Dec 22 04:06 /dev/tty.FTDI.A9BPURYS -> ttyUSB3
lrwxrwxrwx 1 root root 7 Dec 22 04:06 /dev/tty.FTDI.A9MIOH4N -> ttyUSB4
lrwxrwxrwx 1 root root 7 Dec 22 04:06 /dev/tty.FTDI.A9ZFAU3B -> ttyUSB0
lrwxrwxrwx 1 root root 7 Dec 22 04:06 /dev/tty.FTDI.AQ00OLSN -> ttyUSB1

ttyUSB2 is a non-FTDI adapter that doesn’t report a serial number and will be replaced next time I’m in the cold.

If you use the FTDI symlinks in your conserver configuration, they don’t change across reboots, whereas the TTYUSB5 may 
suddenly be a completely different device next time you console to it.

If you want most of the advantages of IPMI for a fraction of the cost (rather than just remote power cycling), then a 
BLIKVM unit is an excellent alternative. (It can even provide power cycling for any standard-ish PC Mobo).

Owen


> On Dec 17, 2025, at 16:51, 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)
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