I’ve build an out of band management solution with a 4 port RS232 hub and a mikrotik mAP. It works perfectly fine connecting to other Mikrotik devices using
/system serial-terminal usb1 channel=0/1/2/3
Even allows simultaneous sessions to multiple ports. This is all great stuff
However I can’t see a way to do an emergency recovery of a device. I can intercept startup and initiate the request to upload firmware via XModem as the receiver but can the host mikrotik act as a XModem transmitter?
Set up serial tcp server in Mikrotik, then you can use any terminal that can do XMODEM and other transfers, like terraterm, to connect and do the job…
It’s even possible to create virtual COM port on windows PC that forwards all traffic to/from the Mikrotik box, very handy if you have to use some vendors non-standard firmware update utility.
Perfect, thanks
Next question though is can I actually upload firmware via serial? because a bit of reading seems to suggest its only for boot loader not RouterOS
For routerboards, it’s only used when updating BIOS and only on some models that do have HW RS232 port. Many recent boards do have UART pins on PCB, but no BIOS and doesn’t even spawn console on it, so it’s completely useless…
And you are correct, AFAIK you can’t upload files to ROS (like update packages) over just plain serial. Netinstall also doesn’t work over serial, only LAN. So if you want to use this for managing other mikrotik equipment, it’s probably not a right choice. Dedicated management port or VLAN is probably a better way to go.
But it’s great for other hardware, like managed switches and other boxes with hardware console you may have around…