Getting an old Computer online with Android Ethernet tethering

Back in the old days we needed to make an Ethernet Crossover Cable to get this to work.

Modern ethernet supports Auto MDI-X, which manages that automagically for you.

> https://en.wikipedia.org/wiki/Ethernet_crossover_cable

I have no idea why we had red cables. There is absolutely no engineering reason why, when ethernet became a thing, that MDI-X wasn't sorted out automatically with some sort of signalling protocol. It was almost certainly a cost thing and that would probably been at the penny level (fuck customers - they don't cost me at the component stage).

To be fair, I don't know why USB had to wait until a few years back to stop acting quantum with its C incarnation. As you know a USB interface with two possible orientations will require at least three insertion attempts.

I grew up with RS232 and expected better. I had to wait quite a long time. USB C is quite good.

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ssl-3 4 hours ago | parent [-]

It was, quite simply, a very different time. This stuff was designed in the nineteen eighties.

Old 10base-T ethernet used one pair of wires for transmit, and another pair of wires for receive (and the other 2 pairs? they did nothing at all!). This worked for the usual case of plugging computers into a hub.

It was Good Enough, and it fit the style of the time.

Could it have been done better? Sure! But that would have added complexity, and adding complexity means even more cost.

And all of this Ethernet hardware was already very expensive. A person who had enough money get into 10base-T hardware probably also had enough money to get a crossover cable in their hands.

The expense is why people like you and I grew up with using RS-232: That was the affordable way to get computers to talk together.

(Let me guess: You also had a run-in with 10base2 once that became cheap-enough, and you also spent way too long soldering together a cable to get PLIP going between a pair of computers)

---

Anyway, auto MDI/MDI-X is pretty much a solved problem these days. At this point there are surely people reading these pages who have been doing stuff with computers and Ethernet for their entire lives and have never needed to know what a crossover cable is.

This, too, is Good Enough. :)

	▲	armada651 4 hours ago \| parent [-]
		I learned what a crossover cable was as a teenager because I was in an electronics store buying an ethernet cable and I picked the cool-looking black-and-red cable. Then the guy behind the counter told me that the cool-looking cable I picked is a special cable and instead handed me a boring grey cable. :(

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ssl-3 5 hours ago | parent | prev | next [-]

USB ethernet and tethering on Android is certainly one way. Keeping the phone powered can present interesting opportunities, but it works well.

There's also other ways.

Like USB tethering. Plug the computer into the Android phone with a regular USB cable that is already kicking around. No ethernet adapter required; the phone behaves as a network adapter in and of itself. The computer keeps the phone charged. This worked at least as far back as the OG Motorola Droid, in 2009. (Drivers may be a fun thing to get working depending on the OS, but that's just a software problem.)

Or: Other hardware that is already laying around. The old home network router that has been hosting generations of spiders for over a decade, in a dusty cardboard box at the back of a closet next to the favorite pair of shoes that are simply too nice to ever get worn? There's a good chance that it's hackable and able to run custom firmware. Stuff a period-correct copy of OpenWRT or DD-WRT or Tomato or [something] into it, and turn it into a wifi client bridge so your old Ethernet stuff can chat on the wifi network. (I've had the big, color HP laser printer at the shop connected this way with a hacked Linksys WRT54G for very nearly two decades so far. Part of me says I should upgrade that box one of these years, but it still works fine and I find this amusing.)

Or: Rube Goldberg minimalism. The Raspberry Pi Zero W that is in the drawer next to the extra key for the Ford that got sold a decade ago (and the spiders; there's always spiders): It runs Linux just fine. It talks wifi. It can talk RNDIS to a USB-connected Windows computer. It can therefore become a wifi-to-usb bridge, wherein the computer doesn't even know that it's talking to a wifi network. Drivers for this are built-ins as far back as XP and are downloadable for windows 9x. (The PC provides the power for the Zero W over the same cable that the data flows over.)

There's lots of ways that many/most of us computer-types can get this done without spending a dime, or ever waiting for a delivery. :)

	▲	userbinator an hour ago \| parent \| next [-]
		Drivers may be a fun thing to get working depending on the OS, but that's just a software problem Android USB tethering uses the RNDIS standard, which I believe goes back to the Windows 95 era, so there's certainly no shortage of driver support.
	▲	stirfish 5 hours ago \| parent \| prev [-]
		"Generations of spiders" threw me there, I thought you were talking about web crawlers.

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bitwize 3 days ago | parent | prev | next [-]

You can make a wifi bridge with a PC, even a Raspberry Pi, running IP masquerading and connecting as a wifi client. I use a Qotom mini PC with 5 NICs for this purpose and connect a whole wired network at my desk.

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mukul_d 3 days ago | parent | prev | next [-]

I recently repurposed a 2010 era Gateway computer with no WiFi. I got Debian installed on it and got it online through hardwire connection. It is running Debain 13 which is the latest release in server mode.

It replaced a 2011 MacBook pro running Ubuntu to host my website at https://www.dharwadkar.com. It is running blazing fast.

Curious to hear your thoughts

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rootsudo 3 days ago | parent | prev | next [-]

Had that similar T series thinkpad 20 years ago too

I would say since it has mpci it’s easy enough to patch the bios and run a newer WiFi chip inside so you’re not locked into this but this is a great workout for older pcs.

Alternatively, many usb WiFi dongles do have windows xp support but yeah with the new standards def something else. It’s a cool workaround!

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bdcravens 6 hours ago | parent | prev | next [-]

Since the article assumes the presence of a WiFi network, you can just use a WiFi to Ethernet bridge, about $40

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teo_zero 4 hours ago | parent [-]

But how do you authenticate to the wifi if the old PC doesn't have WPA capabilities?

	▲	bdcravens 6 minutes ago \| parent \| next [-]
		The PC doesn't. The device does, and the PC is oblivious to where the signal coming along the ethernet wire came from. The issue you're describing would only be relevant is we used a USB (or other connection type) Wifi adapter.
	▲	jasonjayr 2 hours ago \| parent \| prev \| next [-]
		https://docs.gl-inet.com/router/en/4/user_guide/gl-mt300n-v2... These devices have the wifi/ethernet bridge functionality being discussed, (as well as a bunch of other stuff) and are OpenWRT based. Built in openvpn/wireguard as well. We bought a bunch for our team way back when (IIRC they were < $20 USD then) Gl.iNet has other similar more powerful devices as your use case may need.
	▲	ssl-3 4 hours ago \| parent \| prev [-]
		That's a problem for the bridge device to sort out, not the hardwired ethernet gear that it connects. Pre-made wireless bridges generally have web interfaces (and/or dreadful phone apps) to get them set up and chatting the right way. It's a process that's very similar to that of configuring a home network router, except the bridge works in the opposite direction. In this way, the devices with ethernet jacks have no idea what things like WEP, WPA, or wifi even are. And that's kind of the whole point. :)

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AlexDragusin 3 hours ago | parent | prev | next [-]

If it can also be made to sound like an old modem upon establishing connection, that would be great!

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nosioptar 5 hours ago | parent | prev | next [-]

I've had good luck with easytether (was $10 last time I used it). It always worked ootb on Linux systems, didn't require a dongle. System saw it as a USB Ethernet.

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metalman 2 days ago | parent | prev [-]

this is how I do invoicing, but I built an image disk useing "etchdroid", to get an the machine running, so everything through a phone and usb want a laptop now and will look at different OS's