Solved Camping / RVing - Using old router as repeater

[mmacedo]

I'm preparing for camping season with my travel trailer. Many campgrounds offer free Wi-Fi, but the coverage is not great for every site. Four cellphones, sound system using music streaming, smart TV and, eventually, laptops to connect. I would like to improve Wi-Fi signal around the trailer and typing in the campgrounds' SSID and password only once.

I thought about using an old RT-N66U as a repeater running Merlin LTS. To set it up for the first campground it wouldn't be too difficult, but as soon as we arrive in the next one, the RT-N66U wouldn't be running DHCP and I wouldn't be able to access it without resetting. I could manually change to router mode before leaving the first campground, but I know I'll eventually forget about it and then it's done.

The challenge is to simplify/automate this process. What I'm planning:

1. Create a services-start script
   • identify the current mode (is there a NVRAM setting I could check?)
   • if router mode, do nothing and quit
   • if repeater mode, check if there's connection to the campground router (maybe checking if the RT-N66U has an assigned IP address?)
   • if there's connection, do nothing and quit
   • if there's no connection, change to router mode (is there a command to do that?) and reboot. Repeater SSID and password won't be changed.
2. Create a manually-run script
   • input camping SSID
   • input camping password
   • change to repeater mode (command?) with the inputted camping router's credentials. Repeater SSID and password won't be changed.
   • reboot

Then, when arriving in a new campground and turning on the RT-N66U it'll change itself to router mode. I'll be able to ssh from my cellphone and manually run the 2nd script to change to repeater mode. If I input the wrong SSID or password and it can't connect, it'll return to router mode.

Anyone knows the commands to do that or has a better solution? I will be a happy camper

 

[eibgrad]

IMO, last thing you want to do is be *bridged* to some untrusted network. And that's what any repeater bridge does. It means your devices protection hinges on personal firewalls, rather than the router. Given the capabilities of the RT-N66U in terms of third-party firmware, I'd be more inclined to install FT (FreshTomato) and configure it as a WISP (Wireless ISP) router (aka, wireless client mode) so the WAN is virtualized over that wireless client, and the physical wired WAN port can be reassigned to the LAN to make it usable again. Now all your devices reside on their own network and are protected by the router's firewall on the virtual WAN. You also get all the additional benefits of a routed config (e.g., access to the OpenVPN clients, which would be a nice addition in terms of added security/privacy).

 

[mmacedo]

Wow, thanks @eibgrad. It's much better. I'm so used to Merlin that I forgot about other options and I didn't know about WISP. I'll give it a try this evening.

 

[eibgrad]

P.S. A few comments/tips about using FT w/ the RT-N66U.

1. Wireless client mode on FT sometimes has issues w/ certain hardware. Been that way for years. Although some users claim much of those problems are a thing of the past given recent improvements (but I remain skeptical). IIRC, it seems to affect ARM routers more than MIPS (which I believe describes the RT-N66U). In the worst case, it *might* require using DD-WRT, but I personally prefer FT when possible.

2. Presumably you'll configure the 2.4GHz radio as the wireless client for maximum compatibility w/ WISP providers. You can add back the 2.4GHz radio as a VAP (virtual AP) and assign it to the default bridge (br0). Just realize throughput for the 2.4GHz radio will be HALVED since both the wireless client and VAP can't be accessed at the same time (similar to a repeater bridge). So the 5GHz radio for your local clients may be the better choice, assuming they support it.

3. If you decide to use a VPN (which I do recommend), realize the RT-N66U is NOT going to be a greater performer given its relatively low specs (e.g., 600MHz processor). But given your typical WISP provider is probably not offering all that much bandwidth anyway, it's probably NOT a showstopper.

 

[mmacedo]

Hi @eibgrad, I gave it a try last nigh and it worked perfectly well with FT. There are two models of RT-N66U, ARM and MIPS, mine is the MIPS. So, I have the option to install either K26RT‑N or K26RT‑AC on it, but I read the RT-AC doesn't work as a wireless client. I tried the RT-N image and all is fine. I was able to get 100/50 Mbps connecting thru my house network, no increase in latency. Campgrounds won't offer as much bandwidth anyways.

Model

Rev ​

CPU Type

MHz

CPUs

LAN

USB2

USB3

WiFi

Flash

NVRAM

RAM

Build

Notes

Asus RT-N66U

MIPS‑R2

600

1

1Gbps​

2

-

N900​

32MB

64KB

256MB

K26RT‑N or K26RT‑AC

Asus RT-N66U

C1 (B2)

ARM​

1000

2

1Gbps​

1

1

N900​

128MB

64KB

256MB

K26ARM

Supported from 2020.8​

https://wiki.freshtomato.org/doku.php/hardware_compatibility

Wireless Client

The router connects to another router/access point as any other wireless client device would. - Wireless Client mode works for: MIPS devices (SDK5: RT and RT-N images) ARM devices (SDK6 & SDK7) starting with release 2021.5 - This mode is not working yet on SDK6 MIPS RT-AC images. - Only one wireless radio can be used in this mode. Other radio modules, (if present), can be used in Access Point mode. - Disable wireless band steering when using this mode (at least for the default setup. Advanced users could adjust nvram values for band steering). - The recommended security setup for wireless connections is WPA2 Personal with AES. - If no connection is possible using the above, please try WPA / WPA2 Personal + AES. - This is the recommended security setup for MIPS SDK5 (RT and RT-N) wireless client mode).

https://wiki.freshtomato.org/doku.php/basic-network

Yes, the idea is to connect on 2.4G as the wireless client and use the 5G radio for my own devices. I will think about VPN options now.

Thank you so much for your help!