I have a recent model (bought 1-2 years ago) Airport Extreme that, until yesterday, has worked flawlessly.

Starting yesterday, my wireless speeds have tanked. I first suspected my ISP, but that doesn't seem to be the problem - my speeds seem to be fine through my wired devices (albeit subjectively - I haven't measured), just not the ones connected via Wi-Fi.

My setup is:

  • A cable modem with a CAT-6 cable to the Airport Extreme.
  • A CAT-6 cable from the Airport Extreme to a cheap 8-port switch.
  • CAT-6 from the switch to a wall patch panel, which runs under the house to ports in 4 other rooms (where my wired devices live).

The devices that are wired (Apple TV, Amazon Fire TV, Xbox One) all seem to perform fine - I can stream video, download game updates, etc. at decent speeds. My Macbook Pro, Android phone, iPod and iPad are all affected by the slowness, though.

Thinking there was maybe some sort of priority given to streaming packets at some level, I also tried loading the Netflix player on my Macbook (connected via Wi-Fi), but that was also slow, leading me to believe that Wi-Fi, specifically, is the problem.

Some other pertinent details:

  • I have a 200Mbps plan via Time Warner, and a very recent cable modem (the model name/number escapes me) capable of close to 400Mbps. I've achieved the full speed of my plan regularly until yesterday. Nothing in my setup changed, so this almost certainly can't be a result of anything I've done.
  • Strangely, when I reset all of my internet hardware (modem, Airport Extreme, switch) and open a page in a browser on my Macbook, I briefly see fast Wi-Fi speeds. Within as little as a few seconds, though, my speeds drop severely (in the neighborhood of 0-5Mbps). I've even seen the same drop over the course of an online speed test - I can actually watch the "speedometer" needle gradually droop down to almost zero.
  • I need to try connecting my MBP straight to my cable modem to troubleshoot further - I'm sure that will tell me more - but the adapter cable I ordered is still in the mail.
  • I'll try a factory reset on the Airport Extreme tonight or tomorrow, but it would be nice to avoid that if possible.

Are there any common issues that can explain this? Any standard troubleshooting steps that I may not have considered?

  • Lets find out if uninvited is sucking up, use the little app called Who is Using my WiFi from app store itunes.apple.com/us/app/who-is-on-my-wifi/id909760813?mt=12
    – Ruskes
    Commented Feb 10, 2015 at 21:26
  • Please add within your network problem description: 1) how is your wireless network secured, 2) what is your wireless environment: how many of your equipment have Wi-Fi on in your neighbourhood, on which channel…
    – dan
    Commented Feb 10, 2015 at 21:30
  • also konw that the slowest device will dictate the network sharing speed. Thus try turning them on one by one to pin point.
    – Ruskes
    Commented Feb 10, 2015 at 21:33
  • How are your intranet speeds? If you transfer a file between two wireless hosts, what kind of speeds do you see? Also if you option+click the wifi icon in the menu bar, you should see link speed - do you see this drop at the same time the speeds drop?
    – Vitalydotn
    Commented Nov 22, 2015 at 1:46

2 Answers 2


1. Wireless interference

The most common cause of what you describe here is a common wireless interference problem. This probability is pretty high if your network loss of performance was closely related with the move of wirelessly connected computer or of pieces of furniture made of metal or glass (these cause many radiofrequency reflections).

If you want to check this cause of your problem, download iStumbler. Let it run for 10 minutes at the time when you have network problems. Then sort your neighbours network by decreasing signal level. If your channel is the same one as one of your strongers neighbours, then change it for a channel which isn’t among their channels.

I have investigated very complex wireless interference problems since more than 10 years with this exceptionnal quality software.

2. Use of the wrong network interface

The second most popular culprit for this kind of problem is the use of the wrong network interface due to the infamous Automatic network configuration. To check pretty quickly if you are in this case, the easy method is to make a new Network location (which in fact is not a location, but a configuration) where the unique active interface will be your wireless one (No BlueTooth, no Ethernet…). Make all the other interfaces inactives (Make Service Inactive in the little dropdown menu).

The worst case I saw was a MacBook connected through the wireless network but the one coming from the iPhone which was left configured as a hotspot. I let you imagine the nightmare connection since the iPhone was fully used… because the network on the MacBook was bad. In fact this was a 3G phone connection overloaded…and shared.

3. Uninvited wireless scroungers

In urban environment, the third most popular culprit for your kind of trouble is someone who either unwillingly or willingly connected to your wireless network.

This is a potential problem if your wireless network is open, is using one of the fake security functions named WEP or WPA, is using a weak password like 123456 or password on WPA2.

To detect this, use first iStumbler once more. And if you want to go further, check directly on your Extreme Base Station who is connected on it. There is no better and clearer way to see these scroungers.

Don't change your password at random as long as you didn't start a correct analysis. This won't help to understand a problem you might have to face repeatedly as long as you don't see it and kill it. For example, if you are using a fake security function, a neighbour who was able to get your password in 6 seconds, will do the same with any password.


Here are two things to check.

1). Do you have any encryption on your WiFi network? If so, I would recommend changing the password/key and using one that is at least 16 characters long and contains at least three of the four types of characters (lower case letter, uppercase letters, numbers, and special characters like "!", "@", "#", "$", "%"...).

One of your neighbors could have hacked into your WiFi account and could be downloading large amounts of data. If you have Airport Utility 5.x, you can see a list of DHCP clients.

I am also a fan of DHCP reservations. It allows you to more easily spot devices that aren't normally connected to your network.

You can also try MAC address filtering to further enhance your networks security, although I personally find it too much of a hassle. I would suggest that you enable the Guest network for friends to connect to when they are at your house. They'll have access to the internet, but not your local devices.

2) If you have old, legacy WiFi devices that don't support 802.11n, they could be slowing down your network, although not as much as you are reporting. Enabling the Guest network and using that for slower devices could be a way to help the main network.

  • Thanks for your help! I hadn't considered unauthorized users, so I'll try changing the password. I did use a secure password generator to create my existing one, so I would be surprised if someone had managed to defeat it - but it's worth a shot. Will also look into the other tools/approaches you mentioned and report back tonight.
    – Bungle
    Commented Feb 10, 2015 at 21:28

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .