I would suggest looking into ASUS’ Ai-Mesh compatible routers and then adjusting the radio power down as much as you can. Alternatively, you can run Ethernet cables under your baseboard and carpet (if you have some) or fully flat cable across hallways. You don’t need an attic for this but it’s still somewhat disruptive. (But less disruptive than knocking down walls since you just pull up carpet) This isn’t exactly ideal but you’ve got an edge case requiring physical wiring over wi-fi.
___________________________________________________________________-
See: https://technumus.com/wifi-to-ethernet/

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For full context, visit https://forums.cabling-design.com/ethernet/good-wireless-bridge-2542-.htm

On Thu, 14 Oct 2021 04:30:11 +0000, Corey Rocchicciol wrote:
> See: https://technumus.com/wifi-to-ethernet/

I don't see the original question but I just converted Ethernet to Wi-Fi.

[1] I started with an old Windows 10 desktop that has no Wi-Fi card.
It was already on my intranet using its wired Ethernet connection.
But I wanted to move the desktop to a location infeasible by wire.

[2] I happened to have an old unused Linksys WRT54Gv8.1 router handy.
I'm told Linksys doesn't allow "client bridge" mode in that router.
But I was told that DD-WRT firmware does allow "client bridge" mode.
https://forum.dd-wrt.com/wiki/index.php/Main_Page

[3] I flashed the appropriate DD-WRT firmware onto that Linksys router.
(Firmware Version: DD-WRT v24 RC-7 (03/19/08) micro - build 9330M Eko)
https://wiki.dd-wrt.com/wiki/index.php/Linksys_WRT54G_v8.1

[4] I set up DD-WRT in "Client Bridge" gateway mode which was "paired" to
the home router by a MAC address to MAC address connection over Wi-Fi.
https://forums.whirlpool.net.au/archive/89059

[5] This "wireless bridge" gateway connects my wired desktop to my intranet.
The desktop Ethernet port is connected by cable to a gateway LAN port.
That DD-WRT "Client Bridge" gateway connects to my home router MAC NIC.
That MAC-to-MAC connection is done over Wi-Fi as a "wireless bridge."

How to use a spare router as a makeshift Wi-Fi card for a Windows 10 desktop
A. Tested with an old Windows 10 desktop with only Ethernet (no Wi-Fi card).
B. Tested with an old Linksys WRT54Gv8.1 router (flashed with DD-WRT firmware).
C. Tested with a typical Netgear wireless router as the access point & router.
D. DD-WRT is set up as a gateway in "wireless client bridge mode"

The DD-WRT firmware converts Wi-Fi to Ethernet protocols (& vice versa).
1. I started with an old Windows 10 desktop that has no Wi-Fi card.
It was already on my intranet using its wired Ethernet connection.
But I wanted to move the desktop to a location infeasible by wire.

2. I happened to have an old unused Linksys WRT54Gv8.1 router handy.
I'm told Linksys doesn't allow "client bridge" mode in that router.
But I was told that DD-WRT firmware does allow "client bridge" mode.
<https://forum.dd-wrt.com/wiki/index.php/Main_Page>

3. I flashed the appropriate DD-WRT firmware onto that Linksys router.
(Firmware Version: DD-WRT v24 RC-7 (03/19/08) micro - build 9330M Eko)
<https://wiki.dd-wrt.com/wiki/index.php/Linksys_WRT54G_v8.1>

I flashed the firmware using a web browser (I had no need for tftp).
The WRT54Gv8.1 router already has a Linux CFE in the flash.
There is no need for prep or killer files before the initial flash.
<https://wiki.dd-wrt.com/wiki/index.php/How_To_Flash_the_WRT54Gv8>

4. I set up DD-WRT in "Client Bridge" gateway mode which was "paired" to
the home router by a MAC address to MAC address connection over Wi-Fi.
<https://forums.whirlpool.net.au/archive/89059>
<https://wiki.dd-wrt.com/wiki/index.php/Client_Mode>

5. This "wireless bridge" gateway connects my wired desktop to my intranet.
The desktop Ethernet port is connected by cable to a gateway LAN port.
That DD-WRT "Client Bridge" gateway connects to my home router MAC NIC.
That MAC-to-MAC connection is done over Wi-Fi as a "wireless bridge."

These are the steps I ran (so that you can follow them yourself).
a. Run a search on setting up dd-wrt on the WRT54Gv8.1 as a client bridge.
<https://duckduckgo.com/?q=install+dd-wrt+client+bridge+linksys+wrt54gv8.1>

b. Obtain the correct dd-wrt.com bin file to flash onto your WRT54Gv8.1 router.
<https://dd-wrt.com/support/router-database/>
<https://dd-wrt.com/support/router-database/?model=WRT54G_v8.1>
<https://dd-wrt.com/wiki/index.php/Linksys_WRT54G_v8.1>
Manufacturer Linksys, Model WRT54G, Revision v8.1
Supported yes (this means you can install dd-wrt)
Activation required no
Chipset BCM5354 chip rev 2, RAM 8MB, FLASH 2MB
Supported by v3.0 [Beta]Build 44715
<https://download1.dd-wrt.com/dd-wrtv2/downloads/betas/2020/11-03-2020-r44715/broadcom/dd-wrt.v24_micro_olsrd_generic.bin>
<https://download1.dd-wrt.com/dd-wrtv2/downloads/betas/2020/11-03-2020-r44715/broadcom/dd-wrt.v24_micro_generic.bin>
<http://www.dd-wrt.com/phpBB2/download.php?id=4470>
Firmware Version: DD-WRT v24 RC-7 (03/19/08) micro - build 9330M Eko
Save: C:\<path-to>\wrt54gv8p1\
Name: dd-wrt.v24-9330_micro_wrt54gv81.bin
Size: 1708052 bytes (1668 KiB)
SHA256: DC536ED0B91DD22880247958111A42C0289C1A9E9E18603E9548DD511E46BEF0

c. Just in case save the reversion file (let's hope you don't ever need it).
http://download1.dd-wrt.com/dd-wrtv2/downloads/others/tornado/Gv8/vxworksrevert-Gv8-v3.bin

d. Write down the existing settings for your home router.
IP Address = (write down the IP address), mine was "http://192.168.1.1"
Broadcast = yes (it's easier to set up if the SSID is not hidden)
Security = (write down the security), mine was "WPA2-PSK [AES]"
Passphrase = (write down the passphrase)
Gateway Router = (write down the IP address), mine was "192.168.1.200"
Primary DNS: (write down the DNS server), mine was 8.8.8.8
Secondary DNS: (write down the DNS server), mine was 4.4.4.2
Use Router as DHCP Server = (write down the answer), mine was checked
Starting DHCP IP Address = (write down the answer), mine was 192.168.1.2
Ending DHCP IP Address = (write down the answer), mine was 192.168.1.254

e. Decide what IP address is available for your client bridge & Windows PC.
Client Bridge = (I chose 192.168.1.200)
Windows PC = (I chose 192.168.1.201)

Some people will choose to let the home router DHCP assign an IP address.

f. Write down the existing settings for your wired computer.
IP assignment = Manual
IPv4 address: 192.168.1.201
Ipv4 subnet prefix length: 24 (this is the same as 255.255.255.0)
iPv4 gateway: 192.168.1.1
iPv4 DNS servers: 8.8.8.8, 4.4.4.2

Some people will choose to let the home router DHCP assign an IP address.

g. Set your PC IP address (depends on what you have decided above of course).
c:\> ipconfig
Ethernet adapter Ethernet:
Connection-specific DNS Suffix . :
IPv4 Address. . . . . . . . . . . : 192.168.1.201
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
<https://www.partitionwizard.com/partitionmagic/how-to-change-ip-address.html>

Some people will choose to let the home router DHCP assign an IP address.

h. Test your Win10 desktop browser for Javascript capability
<https://jsfiddle.net/>

i. Just in case, enable your tftp client on your Windows 10 desktop PC.
You won't need tftp unless you can't connect to the Linksys via a web browser.

Run > control > View by small icons > Programs and features >
Turn Windows features on or off > [x]TFTP Client > [OK]

After a few minutes it should say "Windows completed the requested changes."
<https://www.omnisecu.com/cisco-certified-network-associate-ccna/how-to-install-tftp-client-in-windows-10.php>

j. Assuming the Linksys WRT54Gv8.1 still has Linksys firmware, reset it.
a. Find a suitable reset tool (a cotton swab with the end cut off works)
a. Plug in the 12VDC 0.5A center-positive power cord
b. A moment later, press the reset button for about 20 to 30 seconds

k. To prevent mistakes, tape over the Linksys WRT54Gv8.1 WAN port.
You won't need the WAN port for setup, nor to use as a client bridge.

l. Connect the Linksys WRT54Gv8.1 LAN port #1 to the desktop Ethernet port.
Use the RJ45 connection on the Windows PC.
You can use any of the LAN connections on the Linksys WRT54Gv8.1 device.

m. From there, I followed almost exactly the directions found here.
<https://forums.whirlpool.net.au/archive/89059>
Using those directions, my results are reproduced below.

n. With a javascript-enabled browser, visit http://192.168.1.1
When/if it asks for your login information, use <blank>/admin to log in.
By default, you'll be placed in the "Setup > Basic Setup" tab.

Make a note of "Status > Router" information.
Firmware Version: 8.1.08 build 02 Oct. 26, 2007
Current Time: Thu Jan 1 00:50:43 1970 (GMT -08:00)
MAC Address: 00:1D:7E:A1:48:45

o. Optionally, additionally restore the Linksys WRT54Gv8.1 to factory default.
Administration > Factory Defaults > Restore Factory Defaults
(that did not change the firmware version when I did it on mine)

p. Upgrade the firmware from Linksys firmware to DD-WRT firmware.
Make sure there is adequate power delivery (e.g., on a laptop).

Then go to Administration > Firmware Upgrade > Browse
Browse to C:\<path-to>\wrt54gv8p1\dd-wrt.v24-9330_micro_wrt54gv81.bin
Firmware Version: DD-WRT v24 RC-7 (03/19/08) micro - build 9330M Eko
Press [Start to Upgrade]
After a while you should see "Upgrade is successful. Rebooting......"
Maybe wait a few minutes before pressing the provided [Continue] button.

q. If necessary, log into the Linksys WRT54Gv8.1 router again.
You should now be in the dd-wrt System Information control panel.
Make a note of "Status > Router" (which will ask for your login/password)
User Name: admin
Password: root
This should put you into the "Status > Router Information" page.

r. Make a note of what this router information page is telling you.
Router Name = DD-WRT
Router Model = Linksys WRT54G v8.1
Firmware: DD-WRT v24 RC-7 (03/19/08) micro
Firmware Version = DD-WRT v24 RC-7 (03/19/08) micro - build 9330M Eko
(RC = release candidate)

s. The first thing to do is to change the Linksys WRT54Gv8.1 IP address.
Bring up the javascript browser to https://192.168.1.1
Press "Setup" and log in as root/admin (if needed)
Go to: Setup > Basic Setup > Network Setup > Router IP >
Set the Local IP Address = 192.168.1.200
Set the Subnet Mask = 255.255.255.0
Set the Gateway = 192.168.1.1
Set the local DNS = 192.168.1.1
Press Save & then press Apply Settings

t. Before you make too many changes, it's maybe a good idea to reboot.
Press Administration > Reboot Router