Upgrading Netgear WNDR3700 V4 from 18.06.1 to 21.02

Added Note about this post: I have decided to upgrade to the latest stable version of 19 as 21.02 is not currently released as stable at the time of this post so I wouldn't want to waste anybody's time as most of the guidance here is geared towards upgrading from 18.06.1 to version 19 - whether or not it is relevant to you is at your discretion. I have not updated the post title as it talks about issues currently with what I was intending to do that may not be an issue by the time that you read this. Kind Regards.


My Network

  1. I'm running a FreePBX/Asterisk Server from home

  2. I also have a small web server that I run

  3. Somehow and through a lot of help I managed to set up the router so that not everything was routed through ExpressVPN (TV Services won't work otherwise).

  4. Web browsing went through VPN.

  5. I have a whole bunch of Port Forwards, the router is manually configured to connect to my ISP through an old Modem that I have.

I'm looking to upgrade to the latest version of OpenWRT and i'm not quite sure what i'm doing. I've been walked through the process once or twice over the years but my memory is pretty poor! I have had some cursory conversations whereby I have been told that i'd be switching architectures so I have to untick "keep settings".

The issues then are:

  1. What can I back up and how do I back it up please?

  2. What needs to be screenshot so I can set it back up later

  3. Does anything look different in the GUI between versions that is going to make the manual config parts more confusing to find "what goes where"?

  4. In the past whenever i've been guided through it I have always been told to connect my laptop to the router - are there any instructions on doing it this way please?

I was interested in potentially repurposing a TP-Link TD-W9970 router but I believe it's not supported - judging by how cheaply they are going on Ebay, I guess they are pretty rubbish! I'd be curious why it wouldn't work too?

Thanks ever so much! Hopefully i've provided a lot of the information needed but obviously i'll update and try my best to answer any questions but hardware just really isn't my strong point! :grinning:

I'm pretty new to the platform, but 4 is probably just running an Ethernet cord between your device and your laptop. For my setup, I have a switch between them so I can easily go between my prototype and a working hacky router on a different platform.

In other words, if I understand correctly, if you can access the GUI/Web Interface, then this is taken care of.

1 Like

You can export your current settings, just to be on the safe side, and make a note/list of all installed packages.
The new fw will not have those installed, and you will have to reinstall them after the upgrade.

Settings can be kept between upgrades.

I wouldn't upgrade to 21, which is a beta, but to latest stable 19.07.7.


Thanks for this but I have been specifically told that I can't keep my settings and that I will need to back them up because network config and wireless config is incompatible. I've been advised to only upgrade to the stable version to so the guy on IRC wasn't apparently offering the best advice to install a Beta version on a router.

Would you say that these instructions are sound advice please? https://openwrt.org/docs/guide-user/installation/ar71xx.to.ath79

I've also looked for a sysupgrade.bin image from https://downloads.openwrt.org/releases/19.07.0/targets/ath79/generic/ but I can't find one for the Netgear WNDR3700v4.


Apples and bananas :wink:

If you go to the latest stable 19.07.x, it'll still utilize the "old" (ar71xx) modules for
wifi, and you should be able to keep the config from your old release.

If you go to the snapshot/beta 21.02, it uses the new ath79 for wifi. I can imagine
you cannot save the settings during this upgrade, due to a completely new wifi driver.

Links to both final stable and latest snapshot can be found here:

1 Like

Thanks for this - I think the most sane option would be to wait for the stable release for 21.02. When is this likely to be please? Thanks so much everybody.

I'd go to 19, out of security reasons.

18.06.1 is really old.

But yeah, if you go to 19 first, you'll have to do some of the post upgrade work twice.
Then again you'll have the most recent release, and still won't have to fiddle around
with the wifi settings.

AFAIK there's no ETA for 21.02, it'll be out when its "done" :wink:

1 Like

It's largely because I fear bricking the router, I have no idea what I am doing in terminal, i've been told Luci has to be installed later and i'm no good with doing Checksums either. Essentially, I have no confidence at all!

I have no idea what I am backing up and what I need to be taking screenshots of or what extra work is involved.

Thanks :slight_smile:

the install Luci later part is for snapshots, and doesn't apply to stable builds, like 19.07.x

1 Like

Yeah, thanks for this but it's also what I need to be backing up too. I'm not sure what I need to back up and then what I need to be taking screenshots of and whether what I back up can simply be dropped back into the /etc/ directory in place of what is already there.

Essentially, the bits above :slight_smile:

Just FYI.

waiting for the next release won't save you from that :wink:

In your router, go to System->Software->Installed tab
there you'll get a list of what's currently installed.

After upgrade, make sure the same packages (version will differ)
are installed, if not, install them (same place as above, Available tab).

That should be pretty much it.

Current settings can be saved through System->Backup / Flash Firmware.

1 Like

Yes, that's an extremely fair comment and thank you for your dedication too. Hopefully, from a dumbass like me when it comes to Hardware, this might be useful to a few others when indeed 21.02 comes out as a stable release - I presume it's the same insertwordache. It's a shame that there is a not friendly "wizard" of sorts, that can say "here's what you need to download" this is what you do after (taking into account anything unique about said router), this is what you need to do next, go to this link before your router reboots and take it from there to get back to me. Dream world but surely possible, even taking into account memory constraints.

Back to the topic in hand, is there anything that I won't specifically get back in the settings and that I need to be taking a screenshot of in Luci? If I remember correctly, it doesn't put back the ISP login details and their unique config for that.

So, I went into Lede flash operations, went to configuration, generated a list, copied that back into the otherwise empty window, left the notes in, hit submit and then went back to actions and generated a backup. I presume that's backup done? Now a list of packages? Thanks.

It wouldn't surprise me if the ISP login was kept too.

But, depending on how you connect to your ISP, you might actually discover you're not able to,
because of missing modules :wink:

Never actually used LEDE, skipped it all together, don't know how it was done there, compared to Openwrt.

What I do is pull up the installed list in one browser tab, flash the router from another tab.
Log in, when the router comes back up, in a new tab, and compare the packages tab to tab.

1 Like

So you'd say my backup effort is correct then? Thanks for the tip as well and port forwards and such like will be preserved or at least backed up? I have a lengthy list as well as unique configs for the two different networks on my router (2.5 and 5ghz)

yes, all should be kept.

only issue would be where you have functionality requiring additional packages, not included in the shipped image. But it should start working once you've got all the packages installed again, and rebooted.

1 Like

Can uploading the sys.bin image be done through Luci then safely? And it talks about a snapshot at your link as opposed to a stable release?

Anybody reading, please do not click the following link until confirmed

Would this be the right link for image I need http://downloads.openwrt.org/snapshots/targets/ath79/nand/openwrt-ath79-nand-netgear_wndr3700-v4-squashfs-sysupgrade.bin

Thanks :slight_smile:

the sysupgrade image, yes, through System->Backup / Flash Firmware.

now you're linking to the snapshot, with the new wifi driver and no webUI, was that intended ?

I'd go for http://downloads.openwrt.org/releases/19.07.7/targets/ar71xx/nand/openwrt-19.07.7-ar71xx-nand-wndr3700v4-squashfs-sysupgrade.tar

but I thought to do a sysupgrade you need a sysupgrade.bin file? No, not intended! Thanks

indeed, but it seems the 3700v4 uses a TAR file.

I checked a whole bunch of older stable sysupgrade images, they're all TARs.


So, can this be used in the same way then? Thanks