[raulo1985]

Hi there. I know this has been asked before, but I have some doubts and I need some advice. I need a couple of builds with specific changes to the factory defaults. I haven’t tried yet, but is it possible to change every factory default (at least the ones on the GUI) with the mod kit? Or for changing those values you necessarily need to compile a new build?

The Story

Just to let you know why I want this, it’s because of a couple of situations. I’m the « tech » guy of the family (you know, the one that everyone thinks can build a NASA spaceship from scratch, when most of the time he just googles what they ask him ), and, long story short, my parents live in a place where they can only get CG-NAT (no cable, just 4G LTE modem, and the company won’t give us an static ip even after offering them to pay for it), and my family also has an apartment where they get dynamic ip (bridged modem). Both places have an R7000 with DD-WRT as main router, and modems are connected directly to the WAN port (both modems are bridged, auto dhcp on DD-WRT WAN).

I want, if possible, to change some factory defaults to be able to upgrade the firmware from my house (via telnet. I know is risky, but I’m willing to take the risk. I won’t be upgrading very often though). The problem is that, in both cases, if I upgrade and factory reset, I’ll lose internet connection and won’t be able to set them up.

- In one build, I would like to only change the ddns settings and enable the remote management setting (with a custom port, for safety reasons), so after upgrading the router not only goes online, but updates the hostname’s ip so I can continue setting it up from scratch by remotely accessing the GUI (perhaps the username and password of the router may also need to be set, to be able to log in by the remote GUI feature). In this case the upgrade would be from an old DD-WRT build, so I think nvram erase is mandatory to avoid issues, but if defaults aren’t changed I won’t be able to connect after the reboot. Is it possible to do this with the mod kit? Or only by compiling a new build? If the answer is compiling, I read that you can pay BS for him to make you a custom build. If that is indeed possible, what’s the right way to get to him for this? Wouldn’t want to bother him much.

- The other case is because, like said, my parents are behind CG-NAT. I’m configuring a site-to-site OpenVPN setup (my router being the server, their’s the client) because ddns is of no use in this situation, and I need remote access to the router and IP cameras. In other words, I need a public IP for that house (dynamic or static), and my only chance being them double natted at ISP side without the possibility to get a static ip is by making a VPN tunnel so their router and devices can be reached through my router acting as a server (with working ddns). The concept is the same as the other situation: if I upgrade, after reboot or nvram erase connection would be lost for good. In this case, I would want to have a build in which factory defaults include the OpenVPN client configuration (including certs and keys), so after nvram erase the router can be reached from the VPN tunnel for further configuration.

Is all of this possible (I guess so, but I’m no expert)? Can these things be done with the mod kit, or compiling is the only answer?

And I’m pretty aware of the risks of doing this, but regardless of that I want to give it a try. To avoid unnecessary issues I would only want those settings changed, I would configure the rest from scratch on both routers, so the other defaults should be left at, well, their defaults. And sadly I don’t have a server or notebook at any of both sites, so Teamviewer is not an option.

I’m not an expert by any means, but shouldn’t this work? I mean, if the remote upgrading process goes without issues, if the only defaults that are changed are ddns and remote management on one build, and the OpenVPN client defaults on the other, that shouldn’t break anything and I should be able to connect. That’s what I think though, I could perfectly be wrong. I’ve done remote upgrading before, but those times I had the possibility to use Teamviewer with a notebook afterwards and enable ddns and remote management to be able to connect after the upgrade. In these cases, the upgrade process could go smooth, but after reboot I’ll end up with unreachable routers . I’m willing to take the risk, and I promise I won’t blame anyone here if I end up with a couple of nice looking bricks

Thanks in advance.

[eibgrad]

What *I* would do given the situation? I would have a duplicate router that I kept and updated locally, then shipped it to the remote location as a "drop in" replacement. The user at the remote end then ships back the old router in the same box. Rinse and repeat. Simple.

This avoids all the nonsense involved in trying to remotely upgrade the router. Because unfortunately, these third-party firmwares (dd-wrt, freshtomato, merlin, etc.) are simply NOT robust enough to deal w/ in-place upgrades. As we tell ppl all the time, you should *always* do a factory reset and manually reconfigure. Which of course is problematic for someone in your position.

[the-joker]

You only need to reset nvram maybe once or twice a year if you upgrade dd-wrt often or someone who monitors development says to do it, lately has been nvram changes, so a reset may be needed in most cases.

Or if you upgrade from a really old build more than or 6 months old to a latest available build.

For best results upgrades should be done minimum once a month since many CVEs are patched more often these days, but thats just me.

Also for firmware upgrades remotely its simple, you upload the firmware to /tmp on router renamed as firmware.bin, after some time the router will self flash and reboot itself.

But from a remote point of view, teamviewer FTW sod shipping and keeping duplicate routers. The way I deal with remote upgrades via teamviewer, use to be UltraVNC, Temaviwwr works better for novices on the other end and you can setup a master password for accessing it, you just need the client number then and the preset password, so resetting the router, isn't so much of an issue since after its reset it gains a WAN IP anywho on reboot, and you be able to reconnect to teamviewer after some time to reconfigure things via the local browser on the remote machine.

[Per Yngve Berg]

It was easy with the Kong builds because he documented the nvram changes.

[raulo1985]

[raulo1985]

[yoyoma2]

[the-joker]

There you go another good tool to the rescue;

Personally Ive never had a setup where I couldn't run teamviewer or some sort of VNC or shell/telnet where routers are attached to. Usually home routers are for homes, where usually there are laptops or some device that supports some kind of tool I can use to remote access.

If I cant attach teamviewer/VNC to any devices on such networks, there are always other ways like some external device running a terminal that is remotely accessible via some tunnel. Ive setup some low power devices that run a basic Linux with a shell for instance as a backup to any access, short of some HW failure, physical access is rare; well was rare, I dont manage those anymore.

TBH managing remote networks isn't new, and making things difficult for yourself by limiting your options could be better managed in future.

But yoyoma's tool may help you without extra steps only some basic ini config entries.

Good luck.

[raulo1985]