I have an Archer C7 configured as access point. It was running OK for several years. Yesterday I decided to update the firmware from 19.07 to 24.10. But I did it in one go with the sysupgrade image. Apparently that is not the recommended approach and I should have updated more gradually. I don't care about the settings, they are easy enough to redo, but the problem is I don't have access to the router physically.
Is there any way I can install 24.10 on it properly now without needing physical access? I can connect to a LAN port though. I can cut/restore power to it as well, if needed.
It depends on how bricked it is. Connect a laptop to the lan port and ideally disconnect or shut down all other devices that are connected to lan ports. Then if you can't get a v4 address, try a v6 link local ping. ping ff02::1%<intname> where intname is the name of the Ethernet port on the OS of the machine you are running the ping on. If you get two replies one of them is yourself and the other one is OpenWrt. The address is derived from the router's MAC address. You can then try to ssh to that address.
You can run firstboot or the GUI "restore defaults" button tor return to default settings, and then log in over the lan cable and configure from scratch. Save a copy of the configuration it is a tar file which you can open for reference but don't copy any v19 config files direct to v24 as the syntax has changed in several places.
My question isn't really clear it seems. I started with a working 19.07 and from there, in a single upgrade went to 24.10. It seems to have worked fine.
However, I now read that I have to upgrade step by step 19->20->21->... because otherwise parts of the firmware may not update properly. Or am I misunderstanding that?
To get to a proper 24.10, it seems I can only flash with the install/factory image, but to do that I need to press a button on the router. Or is there a different way to do that?
Configuration is not a problem; that is easy enough to just do from scratch. My concern is the flashing process.
You are understanding correctly. OpenWrt generally only officially supports upgrades from n-1 while preserving the configs, which in this case would have been 23.05 > 24.10 (or from your angle 19.07 > 21.02; there was no 20.xx version). That said, even the above has exceptions for certain versions with specific hardware -- in those cases, a complete reset/reinstall is usually required. If your C7 was actually using the older ar71xx target (before migrating to ath79), you would have needed a complete reset to go from 19.07 > 21.02 anyway.
Given how much of the syntax has changed in the config files between 19.07 and 24.10, I suspect that you will not get a functional system under any circumstances without a reset to defaults. To do that, though, you will need physical access so you can press the reset button (during the boot cycle) to get to failsafe mode which will allow you to reset the device. Once reset, you can reconfigure from scratch while connected by Ethernet.
OK, that's clear now!
It is working fine, so I'll keep it running until it doesn't or until I upgrade the hardware. It seems the latter may happen first
