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RT-AC86U - Merlin FW 384.16 - Speed Issue?

Discussion in 'Asuswrt-Merlin' started by Jbennett360, Jun 2, 2020.

  1. Jbennett360

    Jbennett360 Occasional Visitor

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    Hi all.

    I have a 420/35 line and for some reason lately I've been having issues where the speed will randomly drop.

    I did have an issue with LAN 1 dropping from 1GBPS to 100mb, but i have since rewired this port and that's no longer an issue. (I checked the network map to see what each of the LAN's where connected at)

    The issue i have at the moment is that the speed will drop, like dramatically drop and the only way to restore this is to reboot the router?

    Before i rebooted the router around 10 minutes ago, speed test was showing 35mb down. I didn't let it go long enough to do the upload.

    Does anyone have any advice as to what could be wrong here?
     
  2. L&LD

    L&LD Part of the Furniture

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    These issues are not 'normal' or fixable with any settings, etc., afaik.

    When was the last time the router was fully reset and configured minimally and manually? Without using a saved backup config file? Without 'blindly' copying old customizations over from a previous router and/or firmware?

    The M&M Config and possibly also the Nuclear Reset guides should be able to get your router and network back to a good/known state.

    Please look for the link in my signature below for those (and more) guides. :)
     
  3. Jbennett360

    Jbennett360 Occasional Visitor

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    To be fair. The router hasn't really been fully reset for along long time. I've ways dirty flashed the latest Merlin over the top.

    The issue really is random, it tends to be a week or so, maybe a little longer before it happens?

    I mean, could it be a cable issue? Even though the LAN1 port is showing 1Gbps? Or is more likely to be a rogue setting that a nuke resolves?

    If push comes to shove I could use the auto reboot, and schedule to reboot once a week I guess?
     
  4. L&LD

    L&LD Part of the Furniture

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    Rebooting isn't a 'fix'.

    No setting will make the router behave as you describe.

    What a 'nuke' will do is make sure the router and the firmware installed on it is using its expected defaults, whether they are visible/exposed to the user or not. :)
     
    royarcher likes this.
  5. Jbennett360

    Jbennett360 Occasional Visitor

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    That's fair enough but what I'm trying to understand or figure out is what could potentially cause that issue and why has it only just started to happen over the last maybe month or two.

    Could it be a cable?
    Could it be a rogue setting?
    Is the router on its way out?
     
  6. L&LD

    L&LD Part of the Furniture

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    As the firmware is updated and bits and pieces of the code gets used in slightly new/different ways (or the variables in that firmware change the roles they play in future vs. past firmware), the router inherently becomes unstable. Particularly when settings and features are set on/off (when testing or just trying them) and the inter-firmware interactions become more complicated than what can be normally imagined.

    Could it be a cable, setting, or the router going 'out'? Sure.

    But even if that was the case, the start of effective troubleshooting would be a full reset to factory defaults and then testing the router continuously with each new customization added over a period of a few days.

    The NVRAM has been shown to not 'take' as it's supposed to, each and every time. That could be one direct reason why the whole experience goes south after a while when each new firmware is flashed 'dirty' over an extended period of time.

    HTH. :)
     
  7. Jbennett360

    Jbennett360 Occasional Visitor

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    Thanks for the reply.

    I'll look at starting with a factory reset and going back to default, I'll probably move back over to official firmwares too, just for the time being to see if that helps at all.

    I can upload the log exported last night just after i rebooted the router? If that might help or show any weird anomaly.

    Hoping it isn't a cable situation. The system I tested it on last night is made up of the following;
    • Cable from the router to an ethernet port
    • Cable around the outside of the house (External CAT6 cable)
    • Cable in and connected to a ethernet mount box
    • Cable from the mount box to a switch
    I've changed the cable (in the last few months, all to CAT6) on..
    • Cable from the mount to the switch
    • Cable from the switch to the PC
    • Cable from the switch to the Wireless Access Point.
    The only cable I haven't changed is the cable from the router to the ethernet port, that's also a 'flat' cable, I might look at replacing that just to be safe.

    I can't see it being a cable issue though really? Like I say, LAN was showing 1gbps in the router network map page, just the throughput was extremely slow.

    Edit: I've changed the cable from the router to the ethernet box. I also unplugged the main modem box and left that unplugged for a few minutes too.
    Edit 2: Changed the ethernet cable from the Modem to the router too.

    Will look at a reset/wipe this weekend. It's not been done in 2 years.
     
    Last edited: Jun 3, 2020
    L&LD likes this.
  8. L&LD

    L&LD Part of the Furniture

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    Maybe someone else can have a look at the logs, but I don't bother with them when the most likely solution is a 15 to 30-minute process (M&M Config).

    2 years is a long time to go between full resets. A lucky combination of the router you have and the firmware upgrades you decided to perform over that time. :)
     
  9. Jbennett360

    Jbennett360 Occasional Visitor

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    Yep. this is my plan at the weekend.

    Flash to latest stock. Wipe/Reset. Setup a basic minimal configuration and see how it goes.

    Edit: Exactly, it's always 'Worked' so i've never decided to do this. I suppose the devices and things in the house have changed too over the time, so it makes sense really to start from scratch!
     
    L&LD likes this.
  10. L&LD

    L&LD Part of the Furniture

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  11. Jbennett360

    Jbennett360 Occasional Visitor

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  12. L&LD

    L&LD Part of the Furniture

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    Raving about stock firmware? I'm not. :)

    Just know that if you do go that route, you will have to do a full reset once again when (not if) you decide to switch back to RMerlin again.
     
  13. Jbennett360

    Jbennett360 Occasional Visitor

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    haha, it's probably because it mentions 'CPU Optimisation' and 'Improved connection stability' not sure what those changes are exactly.
     
    L&LD likes this.
  14. L&LD

    L&LD Part of the Furniture

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    And probably something that RMerlin has already implemented. :)
     
  15. Jbennett360

    Jbennett360 Occasional Visitor

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    Yeah possibly in the .18 release.

    I'll make a decision at the weekend. I guess it does make sense to use the Merlin FW again in some respects.
     
    L&LD likes this.
  16. Jbennett360

    Jbennett360 Occasional Visitor

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    So after 18 days and 10 hours, this has reared its head again for no apparent reason?

    I never got chance to check if it was all ethernet ether out of the router, or just the one that runs around the outside of the house. ( I rebooted before i checked it)

    I'm now on stock firmware. A simple reboot of the router and speeds are back to normal?

    It's bizarre!?

    Maybe I'll just have the router setup to auto reboot once every 7 days or something