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RT-AC86U - slow speeds.

Discussion in 'ASUS AC Routers & Adapters' started by frooty, Jul 17, 2019.

  1. frooty

    frooty Regular Contributor

    Joined:
    Nov 23, 2015
    Messages:
    51
    Hi all,

    I'm having issues with my new RT-AC86U which I upgraded to from my old N66U a few weeks ago & would appreciate any help or suggestions. I live in a rural location so can only get ADSL broadband with a 4mb download & 1mb upload speen, nothing fancy but it suits my needs. I decided to upgrade my old N66U due to it's age & depreciated Merlin firmware to the newer AC86U after reading some good reviews about it, even though it was working fine & was giving me the full 4mb down speed & have relegated it to a repeater upstairs.
    However, since installing the AC86U I've never had the speed above 50% of the 4mb I'm supposed to have, even though my modem reports the full 4mb download speed I'm only getting between 1.5 & 2mb tops from the router either wireless or wired. Here's what I've tried so far:

    Changed all cables to/from the router & modem.
    Reflashed stock firmware.
    Reflashed Merlin firmware.
    Reboots, resets & full factory resets.

    I just can't get the router up to full speed, it's constantly half of what it should be. Any suggestins or ideas would be very much appreciated. Is this normal or have I got a dud router? I'm on the verge of returning this router & reverting back to my trusty old N66U again....

    Thanks & regards.
     
  2. ColinTaylor

    ColinTaylor Part of the Furniture

    Joined:
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    Location:
    UK
    Power off the N66U when testing, just in case that is interfering in some way (I can't imagine this to be the case though).

    Make sure QoS is turned off.

    Disable all custom scripts and configs when testing.
     
  3. ApexRon

    ApexRon Senior Member

    Joined:
    Jun 17, 2018
    Messages:
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    Location:
    Apex, NC
    Your issue is with the throughput speed but you don’t say what the physical connection speed is between the AC86U and your modem. Refer to lower right corner of Network Map screen. It should say 1 Gbps.

    You state “... have relegated it to a repeater upstairs.” Please power off the N66U and check throughput.
     
  4. frooty

    frooty Regular Contributor

    Joined:
    Nov 23, 2015
    Messages:
    51
    Hi Colin,

    Thanks for the suggestion. I switched of the N66U repeater & rebooted the AC86U router just to make sure but I'm still only getting half the speed. QOS has always been off & I got rid of all custom scripts, etc when I last reset the router to defaults. Done the nvram thing too, still no change.
    I've been reading through this thread ragrding issues with the AC86U:

    https://www.snbforums.com/threads/major-issues-w-rt-ac86u.56342/page-5

    I also have been having issues with my printer not being seen by computers on my network, as well as reboots not always working (router stays off) as mentioned there, so I'm of the impression that there's some kind of issue on this model generally tbh. I think it's time to return it & get a different model which is very disconcerting as I've been a fan of Asus routers for years - this is the first time I've had any trouble with them & it seems I'm not alone after reading through that thread.

    I'd like to stay with Asus though so I can make use of Merlins excellent firmware - can anyone suggest a good alternative to the AC86U?
     
  5. frooty

    frooty Regular Contributor

    Joined:
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    Messages:
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    Throughput says 1Gpbs.
     
  6. ColinTaylor

    ColinTaylor Part of the Furniture

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    Location:
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    As your internet connection is ADSL I assume your WAN connection type is PPPoE and your ADSL modem is bridged?

    So I'm wondering whether there's some bug/incompatibility with that type of connection. Presumably you've setup things like MTU to what they were before with the N66U.

    As an experiment you could put you N66U back the way it was before as your primary router, and test that it is working correctly. Then setup the AC86U as a second router attached to one of the N66U's LAN ports (WAN to LAN). The WAN connection type on the AC86U would then be "Automatic IP". Test the throughput again from a PC connected to the AC86U.
     
  7. frooty

    frooty Regular Contributor

    Joined:
    Nov 23, 2015
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    That's correct. When I set up the 86U I went through the auto setup process & it was exactly the same as how the 66U was set up & all settings match. I have reconnected the 66U a couple of times & the speed goes straight back to normal as well as my printer being seen again without having to go through the driver re-install process every time I want to use it.....lol
    I'm not too keen on using the 86U as a AP - it's too expensive for that & I've lost faith in it now I'm afraid. I'm pretty sure it's a dodgy one & will return it - unless anyone else has any more ideas?

    Maybe the AC68U would be better?
     
  8. ColinTaylor

    ColinTaylor Part of the Furniture

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    Location:
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    I wasn't suggesting that using the AC86U as an access point was a solution, only that it might help narrow down the cause of the problem.

    OTOH for such a low internet speed something like an AC68U or AC66U_B1 would be more than enough (and hopefully cheaper).
     
  9. frooty

    frooty Regular Contributor

    Joined:
    Nov 23, 2015
    Messages:
    51
    Yes, I think you're right. My thinking when I bought it was that I was "futureproofing" myself for when fibre finally got round to my location, but if this 86U can't cope with the basics then I guess I'm better off with something less brutal (expensive) for the time being. I might even just stick with the N66U for now.

    Thanks for your input, it's very much appreciated. Bye bye broken 86U.