Bergan77

Q: Airport Extreme AC, slow 5 GHz upload

Hi,

 

I´m having a really strange problem lately...

 

My setup for a year or so has been an Airport Extreme (N-model) as my primary router which handles both DHCP and NAT (ethernet from a fiber converter straight to Airport).

I also have been using an Airport Extreme AC in bridge mode with the same SSID and password so I have complete coverage in my apartment. I´m having two SSIDs, one for 2.4 GHz and one for 5 GHz.

 

This has worked perfekt. Always getting great bandwidth from my ISP (about 95 Mbit/s up and down on 5 GHz and about half on 2.4 GHz on both the N-model and the AC-model, 95-96 Mbit/s with ethernet cable).

 

I had to move the N-model to our summerhouse a while ago so I put the AC-model as the main router with DHCP and NAT on instead of bridge-mode.

 

This is now my problem start.

Suddenly my upload-speed on 5 GHz drops from 95 Mbit/s to approx 10-25 Mbit/s. If I restart the router from Airport Utility then I get my great speed back again. But suddenly without any warning the upload-speed drops again. It could be after 10 minutes or even a couple of days. Most common is that it drops at least once every day after a restart of the router.

2.4 GHz still works fine, not affected at all.

 

Now to the most strange part.

If i put another router (brand doesn´t matter) as my main router and then put the Airport Extreme in bridge mode, then it all works perfekt with high upload-speeds again without any drop?!... I´ve had it like that for almost two weeks without any drop. But as soon as I put the Airport as my main router with DHCP and NAT, it didn´t take long before the drop in bandwidth happened again.

 

I´ve tried EVERY setting in Airport Utility, nothing seem to help. The only thing that helped was putting it in bridge mode, but that is how I want to use it.

 

How is your upload speed on 5 GHz if your Airport is not in bridge mode?

Anyone that has the same problem as me?

 

- Mathias

Posted on Sep 13, 2016 1:29 PM

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Q: Airport Extreme AC, slow 5 GHz upload

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  • by LaPastenague,

    LaPastenague LaPastenague Sep 13, 2016 2:13 PM in response to Bergan77
    Level 9 (52,596 points)
    Wireless
    Sep 13, 2016 2:13 PM in response to Bergan77

    Excellent work analysing the problem.

     

    If you post a bunch of screenshots from the airport utility showing the summary page when you click the AE and then edit.. the Internet, Wireless and Network tab with options on each so we can see the way it is setup.

     

    Yes, we see it all the time. The Airport AC versions have issues with their WAN port. In your case it might be very specific to the wlan to WAN bridge and only on 5ghz..

     

    What is the upload speed on 2.4ghz when the problem happens?

     

    There are almost no controls and no diagnostics that can help you pinpoint the issue.

     

    However there is one major test.

    Here is the question.. is this problem WAN or LAN?

     

    What I need you to do is test the speed of the 5ghz upload by copying a file to another computer.. or a hard disk plugged into the Airport would also be ok. The second computer must be plugged in by ethernet if you use that so you are measuring speed over the single wifi hop.

     

    If both LAN and WAN speed slow down there is a possible fault in the wireless or it is swapping to a poor channel. If you haven't played with channels before then do try one down low.. 40 say.. and say 161 or 149. Tell me the link speed on the computer is staying the same.

    It would help to run the wireless diagnostics in the Mac during these tests.. before and after.. using the Tools like scan and performance. I want to see if the 5ghz has swapped channels to a lower speed setup.

     

    Have you set IPv6 to link-local only?

     

    There is an alternative to bridge if you want to bypass the problem.

     

    Using your alternative router to handle NAT..  set a restricted range of IP addresses for its DHCP server.. then use static IP on the Airport and DHCP.. and tell me how that works.

     

    This is another post I did with all the screenshots to do the setup.

     

    https://discussions.apple.com/message/25135547?ac_cid=tw123456#

  • by Bergan77,

    Bergan77 Bergan77 Sep 14, 2016 12:19 PM in response to LaPastenague
    Level 1 (8 points)
    Wireless
    Sep 14, 2016 12:19 PM in response to LaPastenague

    Thanks for the advice, I will try the NAT and DHCP option later.

     

    I don´t think it´s the LAN. I have installed Ookla Speedtest Mini on my QNAP NAS so I can test the local bandwidth and it shows good speed all the time, about 200-400 Mbit/s down and 100-300 Mbit/s up and it doesn´t matter if the problem is there or not.

     

    Some screenshots from my local Speedtest.

     

    When there is no problem:

    speedtest_mini_good.png

    When there is problem:

    speedtest_mini_problem.png

    Regular Speedtest.

     

    5 GHz and no problem:

    http://www.speedtest.net/result/5631120758.png

     

    5 GHz and problem:

    http://www.speedtest.net/result/5631226093.png

     

    2.4 GHz and problem:

    http://www.speedtest.net/result/5631441533.png

     

    As for you other questions:

    IPv6 is set as local link.

    Changing channels has very little impact on bandwidth or TX-speed (usually around 500-800 Mbps).

     

    Screenshots from Airport Utility (in swedish).

    AirportU3.png

    AirportU1.png

    AirportU2.png

    The drop in bandwidth happened again today, so right now it has happened every day for at least a week.

     

    - Mathias

  • by LaPastenague,

    LaPastenague LaPastenague Sep 14, 2016 2:34 PM in response to Bergan77
    Level 9 (52,596 points)
    Wireless
    Sep 14, 2016 2:34 PM in response to Bergan77

    Again excellent and careful analysis tells us this is internal problem on the Airport. It is purely the WLAN 5ghz to WAN bridge that is faulty.

     

    All your screenshots are fine and there nothing that can be fixed there.

     

    If your AE is within warranty or applecare I would return it as faulty.. point to this thread for evidence of the fault.

     

    I would not be at all surprised if it happens on the new one.. if not immediately after 12 months of operation.