WNDR3700 - Upgrading AND keeping the configuration in tact

Is there a way that I can upgrade the firmware without losing my current configuration and messing everything up?
I have assigned it as a switch and the IP address is different than my main router and I'm worried that upgrading it would reset everything to their defaults, give me an IP address conflict, reset the router to act as a router (with DHCP enabled) and erase all the settings that I've changed to get it working the way I want it to. Which is important to know, I do have a 1GB USB stick attached as persistent storage instead of writing the files to the router's memory, it just places them on the USB stick.

Hostname OpenWrt
Model Netgear WNDR3700
Architecture Atheros AR7161 rev 2
Firmware Version OpenWrt SNAPSHOT r11536-cde8c2f2fb / LuCI Master git-19.322.30592-b1cb0d6

I do find that there are tons of packages that I have installed that do need an update.
I guess I should take version 19.07.2 for the AR71xx architecture and take one of these?image

You'll use the sysupgrade image.
Regarding the configuration you can try to keep it, but it will be only the configuration, not the packages you installed. For the latter you can use this script.
Normally upgrading between major versions (18->19) carries a small risk of configuration incompatibility and configuration from scratch is suggested. I am not sure since when is your snapshot though.
So better disconnect it from the main router first, then upgrade, configure, and reconnect it back.

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So it may put me back at square one, right? Then I'd have to set it up all again?
As for the images, should I be using the AR71xx or ATH79?

19.07.x is the final release to ship with ar71xx images, looking forward you need to switch to ath79 (the configuration files between ar71xx and ath79 differ in some crucial parts and are not compatible), so if you start from scratch, now would be the time to do it once (with ath79).

For wndr3700 the ar71xx and ath79 config files are actually compatible.
I constantly jump between them due to my community build for wndr3700.

(But your USB extroot may make the sysupgrade somewhat more difficult)

Is there a way to go from snapshot to stable or stable to snapshot, actually?
Also, I did find an article on how to bring the extroot back after the upgrade.

I go all the time back and forth, 2-3 times per week. You may need to "force" the sysupgrade on LuCI GUI or sysupgrade command line, as the device ID in image metadata has changed, but the same config itself works ok with 19.07 and master for WNDR3700/3700v2/3800.

(But I have never used extroot, so that may cause you some extra work)

No special way, just upgrade the new image.

From my experience upgrading a router with extroot doesn't affect the upgrade procedure. I keep the settings during upgrade (if I don't do a major release upgrade) and then follow the extroot procedure from the beginning: install modules for usb, mount usb, copy overlay, fix fstab, umount, reboot.

I backed up all the settings from when the router was running the older snapshot release and then I restored them after the upgrade to the stable release, now I'm getting errors. I should really start from scratch again but I don't know how I did it.
Maybe you guys can help me out?
I'd like to do the following...

  • Run the router as a client (no DHCP or DNS servers, etc.) The 'main router' (ASUS RT-1900P running Asuswrt-Merlin) will be doing all the important stuff.
  • Have extroot going. (~3MB of free space is not a lot of space to work with)

I had it all running with the backed up files but then when I tried to 'update' the packages (from the software tab), I got tons of errors and the router wouldn't boot anymore. :frowning:
So, I had to place the stable image back on by using TFTP.
Now it's just sitting there at (which conflicts with my main router) and has no internet access and only 3MB of storage space.

After this, I'm going to take note of all the steps needed and print it off so I don't loose all the info..... again.

Do a restore to factory defaults, either from Luci or firstboot in SSH.
Setup the internet connectivity, resolve the IP conflicts.
Then setup your extroot.
After you have the extroot, install the missing packages and restore the configuration manually, not from Luci or sysupgrade.

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Mass upgrading packages is dangerous. The feature is meant for updating individual packages, e.g. due to security updates, bit trying to update lots of packages will lead to trouble.

Quite possibly you ran out of flash space, and that semi-bricked your router. (Packages that were in the firmware cannot be deleted, so upgrading them means actually installing a second version on flash... Wndr3700 has only 8 MB flash, and only a few hundred kB are typically free...)

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I could set it up as a switch and give it an IP address of something other than
As for the factory defaults, I just finished flashing it with TFTP, so not sure if I still need to do that.

Yes, I did see a few errors saying it had to install a second copy of the files in a different folder.

In that case it's not needed.

Okay, I got the internet back. I'm actually connected to my WNDR3700v1 and it's running through my 'main router' to get to the cable modem. :slight_smile: