My AirPort Extreme cuts the speed off more than in a half! What’s the problem?

Extending by Express is really bad idea.. it has 100mbit ethernet ports.. so your 200mbit internet will never get beyond about 90mbit/s max.. and extend wireless will halve the wireless speed at least.. could be more.

Plug a computer directly by ethernet to whatever modem or fibre box your ISP has given you and test the speed.. This is first essential test to make sure your actual speed is what you bought.. !!

Assuming that goes correctly.. then reset the Airport Extreme to factory and plug it into the modem/fibrebox/router whatever .. redo the setup.. and plug in one computer by ethernet.. everything else off.. including the express.. now do the test again.. what speed do you get.. you should get close to your direct speed.. minus perhaps 10%.

No luck then what actual model is the modem router that your ISP supplied.

Expect major issues if you have arris cable modem.. and a gen6 Extreme.

What model is your Airport Extreme? I am assuming the latest tower one..

But I plugged my MacBook Pro directly to the internet cable and the speed as fast as it should be..

Excellent.. that is pretty much the proof that we needed that your internet is working fine.

I am guessing your connection is fibre and somewhere there is an ONT box (Optical Network Terminator) .. fibre goes in and Ethernet comes out.. if you live in apartment building it could be installed in basement etc.. which is fine. All I need to know is the exact type of internet you are getting.

And how do you authenticate.. Do you need to use PPPOE with username and password.. ??

Or do you need just to use DHCP which means IPOE??

I am also guessing you do have a public IP on the Airport WAN interface.

Is your ISP using IPv6? Could they have been working on a change over when things went bad?

So I’ve been using my AirPort Extreme for almost two years now.

So it sounds like the airport could well be faulty. Or the ISP is switching from IPv4 to IPv6 or similar event.

Reset the AE to factory as I suggested would be the first step in fixing it.. or determining if the AE is having trouble.

Next step would be to use alternative router as you suggested.. A TP-Link should be fine.. that will help us quickly determine that the AE is actually faulty. If so you should claim warranty if that is possible or if you have applecare on a computer, iPad, or apple tv the AE should be covered.. however we note Apple has lately been forcing customers to complain to their consumer protection in each country.. which if you have a clear documentation I would do.

We have seen a fair number of AE break down after a year or two in service. The WAN port fails in some cases..

One way to test this would be to bridge the AE.. and run the ethernet link that is now plugged into WAN to a LAN port.. and again plug the computer into another LAN port on the AE.. test if it works ok.. note only one client can join in the internet so just the computer you test.. if it gives full speed.. and also test by wireless.. if that also gives full speed.. but the WAN connection when you swap back is slow.. that is a standard fault.. using a different router and then the AE in bridge just for wireless.. might be your only option.

I will keep an eye out for your responses.