I used an previous router as a devoted sensible domestic community, and it solved two issues without delay

A router improve manner the previous router will get tossed in a drawer or thrown away. However I attempt to repurpose it. A few months in the past, I grew to become my previous ASUS RT-AC66U router into an get right of entry to level. Later, I repositioned my major router, after which protection stopped being a subject. Clearly, that supposed sending the older router again into the drawer.

I determined to proceed the use of my previous router on my community till it lasts — in the end, it nonetheless labored, so I set it up as a devoted sensible domestic community. Steadily, I spotted the way it solved two issues without delay for my domestic community.

Coping with a messy sensible domestic

No plan however best gadgets

I’ve been slowly development my sensible domestic over the last few months. Like many of us, I by no means in point of fact deliberate it correctly and simply saved on including gadgets. Prior to I fired up House Assistant for the primary time, my domestic already had a wise TV, a Fireplace TV, an Apple TV, a HomePod, Philips Hue bulbs, and a few different issues.

All the ones gadgets continue to exist the similar community as my telephones, laptops, and desktop. I by no means stricken checking the community chaos and chatter led to by way of the consistent plugging in of ESP32-based gadgets and sensor nodes. On the other hand, the protection implications of inexpensive sensible gadgets sharing the community with my private gadgets were nagging at me for some time, and I wanted a excellent explanation why to after all do something positive about it.

For a few months, I ran an IoT VLAN for sensible gadgets, and it labored wonderful. However I at all times saved second-guessing the firewall regulations I created in OPNsense on Proxmox. Seems, I had a protracted, laborious listing of regulations. So I attempted a distinct method with a particular piece of {hardware}.

An previous router will get a devoted activity

Giving it a moment lifestyles​

Although the AC66U is a Wi-Fi 5 router that you just wouldn’t purchase these days, it’s nonetheless helpful. It has a tight construct high quality and dual-band strengthen. The only the most important explanation why I nonetheless thought to be it: strengthen from neighborhood firmware initiatives for older Broadcom chip-based routers. I picked FreshTomato because it continues to obtain updates even in 2026 and provides features that have been absent from maximum inventory firmware. That’s exceptional for such previous router {hardware}.

The most efficient section was once that it didn’t price me the rest to hold out this mission. I already owned the router and had a few Ethernet cables sitting in a field. So if you have got an previous router amassing mud, put it to excellent use. However first, test FreshTomato’s {hardware} compatibility sooner than flashing it.

Putting in place an previous router as a wise domestic community was once simple

There was once a catch, despite the fact that

I flashed the newest FreshTomato 2026.2 firmware at the AC66U and attached it to my major router (AX88U) the use of an Ethernet cable. The bodily setup was once simple: one finish of an Ethernet cable plugged right into a LAN port at the major router (AX88U), and the opposite into the WAN port at the AC66U. I switched the WAN at the AC66U to DHCP mode, and it routinely assigned an IP deal with from the principle community. With the web running thru AC66U, the primary hurdle was once cleared.

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In FreshTomato’s interface, I renamed the two.4GHz SSID to Sensible House and set a password. Since maximum IoT gadgets perform on 2.4 GHz, I grew to become off the 5GHz band totally. For the digital interface (Complex -> Digital Wi-fi), I assigned a devoted subnet cut loose the only at the major router. That’s to isolate the sensible gadgets totally from the principle community on the routing degree.

One fair catch: connecting the older router to the principle router the use of an Ethernet cable. I was hoping to arrange and attach my previous router to the principle router wirelessly, with out working a cable. Contemporary FreshTomato builds got rid of wi-fi consumer mode for the MIPS RT-AC gadgets. A cable is a extra dependable resolution. After putting in the community, hanging House Assistant over grew to become out to be but any other determination.

Transferring House Assistant to a wise community is hard

Making a devoted sensible domestic community manner the sensible domestic hub should be on that community as neatly. When you run House Assistant on a Pi, then attach its Ethernet port to the LAN port of the older router. However should you run House Assistant in a VM, as I do, you’ll wish to use a moment NIC.

Since my mini PC had a moment NIC to be had, I plugged it into the LAN port of the AC66U router. In Proxmox, I created a brand new Linux bridge (vmbr1) for that NIC and connected it to the House Assistant VM as a moment community adapter. House Assistant now has one foot on each networks. At the number one community, it manages media avid gamers and receives instructions from my telephone to regulate Apple TV and HomePod.

In the meantime, it stays reachable thru an IP on a distinct subnet and connects to the sensible domestic SSID. I arrange a DHCP reservation at the older router to make sure House Assistant’s IP by no means adjustments. Operating House Assistant on a Raspberry Pi? Simply attach the Pi without delay to a LAN port at the older router. For the reason that Pi best has one Ethernet port, transfer House Assistant totally onto the IoT community, and also you’re completed.

Two issues were given solved, one I didn’t be expecting

Isolation and peace of thoughts

The primary drawback is safety. The sensible gadgets at the moment are on their very own remoted subnet. Even though an affordable sensible plug will get compromised, it could actually’t contact the rest on my major community. House Assistant best reaches sensible gadgets thru a separate community interface, while IoT gadgets can’t start up connections to the principle community.

The second one drawback that infrequently will get sufficient consideration is repairs overhead. Operating a house lab is my pastime, however keeping up enterprise-grade complexity for a house community isn’t. I attempted putting in VLANs the use of OPNsense on my mini PC sooner than settling in this setup. Regardless that it sounds technically awesome, I continuously appeared over my shoulder, questioning if I left a hollow with a lacking firewall rule. Or worse, finding {that a} newly added software had quietly damaged one thing I hadn’t accounted for.

That roughly continual uncertainty is laborious and defeats the aim of a house community that simply works. The previous router sidesteps all that. With two routers, I am getting two networks with herbal isolation and no firewall regulations to audit or moment bet. The house community is the only I totally perceive and will troubleshoot with a bit of luck when one thing stops running past due at evening.

On occasion the most straightforward resolution is the precise one

Like Occam’s Razor idea, the easy resolution is the proper one. An previous router and an Ethernet cable are sufficient for domestic segmentation. That’s how I will have to’ve constructed it from the beginning. It’s now working reliably the use of {hardware} I nearly threw away. I don’t have to write down any firewall regulations or handle tight VLAN configs. For my domestic community and residential lab, peace of thoughts is price greater than architectural magnificence.

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OS

Home windows, macOS, Linux

iOS appropriate

Sure

Android appropriate

Sure