Forward internet through access point to clients.

[PlainJack56]

Is it possible to forward internet from a connected WIFI network through an access point.

like if I connect to my homes router then start an access point from my esp32 would I be able to give the clients that connect to the access point internet from the routers WIFI?

I'm using the network library btw but if you have any libraries that might work for this let me know.

[Josverl]

No,
the MicroPython firmware does not include an IP NAT router.
You could build this in C in pure ESP-IDF, but I expect it will be very very slow not very fast.
Edit: not that bad actually: esp32_nat_router

If you only want to expose a single port in an Application proxy style you could do this using asyncio,
But you'll still need to think through you network and name resolution settings.

#untested snippet follows

import uasyncio as asyncio

async def pipe(reader, writer):
    try:
        while True:
            data = await reader.read(1024)
            if not data:
                break
            writer.write(data)
            await writer.drain()
    finally:
        try:
            await writer.aclose()
        except:
            pass

async def forward(local_host, local_port, remote_host, remote_port):
    async def handler(r, w):
        rr, rw = await asyncio.open_connection(remote_host, remote_port)
        await asyncio.gather(pipe(r, rw), pipe(rr, w))

    return await asyncio.start_server(handler, local_host, local_port)

async def main():
    # Listen on ESP32:8080 and forward to 192.168.1.50:80
    await forward("0.0.0.0", 8080, "192.168.1.50", 80)
    while True:
        await asyncio.sleep(3600)

asyncio.run(main())

[shariltumin]

Well, it's not completely hopeless. I have custom-built firmware that provides NAT routing from the access point (AP) to the station (STA).

MicroPython v1.27.0-preview.45.g1588c455c.kaki5 on 2025-08-18; ESP32 NAT (KAKI5) with ESP32
>>> import test_nat_2
Sta not ready!
Sta not ready!
Connected to external Wi-Fi with IP: 192.168.5.15
AP mode active with IP: 10.10.6.1
Start NATRoute
Stop DHCP server on AP first.
NAT Router: Start DNS on AP from STA.
NAT Router: Enabling NAPT on AP interface.
NAT Router: Start DHCP server on AP.
NAT Router: Setting default network interface to STA.
AP: ('10.10.6.1', '255.255.255.0', '10.10.6.1', '192.168.4.1')
STA: ('192.168.5.15', '255.255.252.0', '192.168.4.1', '192.168.4.1')
>>> 

Then, I connect my phone to the access point (AP) and gain network access with an IP address of "10.10.6.2". I can play YouTube videos in 1080p quality through the ESP32 without any problems.

[Josverl]

Nice,
I could use that as a simple range extender with bonus sensors in my cellar

how much memory does that leave for MicroPython use ?

[shariltumin]

I'm thinking of setting up an access point (AP) with the ESP32's proprietary long-range (LR) mode and letting the NAT router handle the routing. This way, you can have several long-distance ESP32 MCUs as sensors and actuators.

Give me some time to set up the Git repository, and I will report back here on my progress.