Weird problem after firmware upgrade - AC1900P

[Bill Waggoner]

I decided today to upgrade the firmware on the router. I did all the "right" things ... I saved the config in the web GUI, I updated the NVRAM-SAVE scripts and ran them on the USB stick.

I then upgraded the router rom 3.0.0.4.385_20433 to 3.0.0.4.386_43129. That's when the weirdness started.

I could access the internet but not the web GUI, it never fully responded. SSH in and all looked OK. The IOS APP also couldn't connect. A couple of reboots and still not right.

So, as is often suggested, a factory reset and restore the config. So I did the reset, confident that I had TWO settings backups ... I needed three I guess.

First, the settings restore in the GUI failed. It didn't like the file no matter what I tried. Looks like it is corrupt.

So, I enabled telnet briefly and tries the nvrame-restore.sh script. THAT FAILED! A syntax error is the restore script at line 66.

Strike two.

Well, my config isn't that complicated so I copied the settings txt file and went through that to put back the few changes that I've made, some DHCP assignments, DNS changes, nothing earth shattering.

Now all is working on the LAN and I have internet access OK I think. BUT, isn't there always a BUT?, on the main web page and in the IOS APP it says Internet Access Disconnected, despite the fact that it isn't actually disconnected and I see the extenal IP and good numbers in the Internet Status window.

Any thoughts?

 

[cyberwiz]

If you upgrade to a new major version of the firmware for which a factory reset is called for, and you then restore the config from a file that was saved using a previous firmware version, you basically "undo" the factory reset. The factory reset is meant to put default values as appropriate for the new firmware, in all configurable options. When one restores a config file saved from a previous version, into a new major version, that restore puts the values that were appropriate for the previous major version in all configurable options of the new firmware. Some of these values may no longer be appropriate for the new version, which can cause all sorts of weird behavior.

I'd suggest doing another factory reset "by the book" and then just manually making all necessary configuration changes again. Then test to see if it behaves well.
If that doesn't work, go back to 3.0.0.4.385_20433 and restore your config file from that same version.

 

[Bill Waggoner]

My attempts to restore the config failed in both cases so I did do the manual config changes but now I am getting very strange results. Not only does the router claim there is no internet connection despite that the connection is working fine but some of my hosts can't see (ping) the router. It is most weird. I'm going to revert ... and because neither config was saved in a useable form I have to reapply manually.

 

[cyberwiz]

I think that even if the attempt to restore the config failed, some of the settings may have been restored. I therefore think it is worthwhile to try a factory reset and then to manually set the necessary configuration options. As you wrote your configuration isn't that complex, it seems a worthwhile experiment to me.
If you do revert, I'd try to restore the config from the file. It is very well possible that your config seems unusable because you tried to restore the config from 3.0.0.4.385_20433 on 3.0.0.4.386_43129. If you attempt to restore the config that was saved in 3.0.0.4.385_20433 on that same version (after you revert), you may find it just works.

Good luck!

 

[Bill Waggoner]

I reverted. The settings that I saved prior to the upgrade is not a text file. All my other saves are text, this one isn't. I have no idea what happened to it. When I try to use it for a restore it complains about the file format.

I've restore all of the functions that I am most concerned about, the internet now shows as connected again. I lost my VPN settings but I can rebuild that easily enough, I don't use it often.

I'm very confused about the settings saving not being useable. I tried again using a different browser and got the same result. The file begins with "HDR2" but after that is binary.

And I have used the nvram save utility to save the config to the USB stick and that looked good but wouldn't restore due to a shell syntax error. I may pursue that later ...

 

[bbunge]

I reverted. The settings that I saved prior to the upgrade is not a text file. All my other saves are text, this one isn't. I have no idea what happened to it. When I try to use it for a restore it complains about the file format.

I've restore all of the functions that I am most concerned about, the internet now shows as connected again. I lost my VPN settings but I can rebuild that easily enough, I don't use it often.

I'm very confused about the settings saving not being useable. I tried again using a different browser and got the same result. The file begins with "HDR2" but after that is binary.

And I have used the nvram save utility to save the config to the USB stick and that looked good but wouldn't restore due to a shell syntax error. I may pursue that later ...

You made a major jump in firmware and in some respects technology. The web gui access block was likely the router doing some database maintenance. You should have waited a bit. The old settings file will not work as you now have an encrypted NVRAM. You may not be able to go back to the old firmware version where you could use the old settings file. (Oh, you only need the one settings file to restore router settings)
Best recommendation is to finish the manual config now that you have the new firmware. Better to have all the security fixes...

 

[cyberwiz]

It seems to me that your config file is in one of the obfuscated formats. If you're not concerned for the privacy of any of the information in the config file, you can try an online obfuscation decoder here: https://alex.wittig.name/en/90Software/80Asus Decoder/
Or you can download and run this code locally (much safer): https://github.com/BigNerd95/Asuswrt-Configs-Deobfuscator/blob/master/awrtconf.py

 

[OzarkEdge]

I decided today to upgrade the firmware on the router. I did all the "right" things ... I saved the config in the web GUI, I updated the NVRAM-SAVE scripts and ran them on the USB stick.

I would upload the firmware manually, reset it using the router webUI Restore w/Initialize function, and configure it from scratch.

OE

 

[Bill Waggoner]

It seems to me that your config file is in one of the obfuscated formats. If you're not concerned for the privacy of any of the information in the config file, you can try an online obfuscation decoder here: https://alex.wittig.name/en/90Software/80Asus Decoder/
Or you can download and run this code locally (much safer): https://github.com/BigNerd95/Asuswrt-Configs-Deobfuscator/blob/master/awrtconf.py

That seemed to work mostly. It complained about a randkey but dumped most of the config as far as I can tell.

Any idea why ASUS couldn't load it? It's a little disconcerting to have a "Save" function that creates a file you can't "Load" ... I was under the impression that that was the purpose of the Save, no?

 

[ColinTaylor]

And I have used the nvram save utility to save the config to the USB stick and that looked good but wouldn't restore due to a shell syntax error. I may pursue that later ...

It sounds like you're either using John's old utility for Merlin's firmware or the newer version by Xentrk. Neither one was written to be compatible with the stock firmware version you were using.

 

[cyberwiz]

Any idea why ASUS couldn't load it? It's a little disconcerting to have a "Save" function that creates a file you can't "Load" ... I was under the impression that that was the purpose of the Save, no?

This is indeed quite worrying. A quick search did not turn up any other reports of people unable to load a configuration saved with the same firmware version.

Is it possible you previously did another major firmware upgrade (say from 384 to 385) without doing a factory reset? Or from Merlin to stock? This could have put the router into a state where part of the functionality wasn't working properly.

Please note that the config file format starting with "HDR2" and continuing binary isn't new for 385; I checked my own config files and can confirm that the config file format saved by earlier stock firmware versions as far back as from 2017 are in this same format (starting with "HDR2" and continuing binary). I have no issues restoring my configs that are saved in this format, but I never restore a config saved with a previous firmware version (whenever I do a major firmware upgrade, I do a full factory reset, reconfigure manually, and then save my config). As far as I know, the save/restore functionality is meant to be used only by the same major firmware version and isn't designed to be forward or backward compatible.

Perhaps the other config saves you have in text format were made with a nvram save utility and not with the built-in config save? As @ColinTaylor wrote above, those utilities were not meant to be compatible with the stock Asus firmware, so it is not surprising you couldn't restore those either.