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AC68U Popular speedtest sites show full speed, but actually downloading files are slower than dial-up.

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flyingwolf

Occasional Visitor
Hello everyone.

As alluded to here in this post I am having an issue that I think may be an actual bug.

The equipment is an RT-AC68U with Merlin 386.3_2 on it. When upgrading I followed all of the best practices as suggested in this forum including multiple firmware reinstalls and resets with the box checked.

On the 2nd of November, I was having major internet slow down issues due to 4 of the 5 people in the house gaming and downloading updates and it was slowing my machine down.

So I made what I think may have been a fatal mistake and enabled QoS.

However, all I set was the priority via drag and drop in the QoS - WAN/LAN Bandwidth Monitor page. I did not enable QoS on the QoS tab, and in fact, when I tried it would not apply, after choosing a type or custom it would not let me hit apply. So I simply left it and on refresh, it was still showing as off.

Immediately after that, I noticed that the videos I was downloading for work slowed to a crawl. The speed showed in kbps it was so low.

So I check fast.com, full speed, 990Mbps (I have gig fiber) remoted into the server, no issue there, remoted into a different machine and connected to the server and confirmed full speed downloads from the server that meant my network or my ISP.

I did a lot of troubleshooting, the router I was using started acting up and slowing down and not wanting to work so I grabbed my spare fresh AC1900, flashed it, let it get stable, installed the firmware noted above, used every bast practice as per @L&LD noted here, https://www.snbforums.com/threads/ax88-packet-loss.62891/#post-563326 and here, https://www.snbforums.com/threads/merlin-on-asus-ax86u-question.74295/#post-708304 and finally switched out the old router, with this new one.

I gave it time to boot up and become stable, rebooted it one last time with everyone connected, let it come up stable, and then did my tests.

Once again the popular speed test sites were fine, fast.com speddtest.net, even my own ISP's speed test site which is just a local of Ookla all showed exactly what I expected, at or slightly above 1 gig down and 250meg up.

I then went to testmy.net and ran their test from their main page, the combined test. 128kbps down, 40 megs up.

I did this from multiple machines in the home, wired and wireless, all with the same results.

I then enabled a VPN (proton) on my machine and ran a test, as expected I had slower speeds, but they were consistently 250+ megs down and about 75 up on the popular sites, and to my total surprise on the testmy.net site it was the same! Not quite as fast, but consistent and strong.

I then restarted the download of my videos and they were running at the expected speed minus overhead, averaging about 100 megs.

Finally, as a last-ditch effort I ran a direct line from the ONT on the side of my house into my main machine and redid the testing, everything worked as expected with the Merlin router, not in the mix.

In a final call for help, I called my ISP and got ahold of network engineers there (remember to say shibboleet to get a competent tech) and we ran through my troubleshooting, did some work on their end, saw some funkiness, and decided to roll a truck out.

The truck just left 2 hours ago. He came, checked the speeds, saw the incoming light signal was good, replaced the ONT with a new item from a different batch as some from the batch I was first given had proven to have problems I had yet experienced, but no point in not switching it out.

We let it boot up, stabilize, he ran a test with his tools, I ran a test with mine, same issue, popular sites, and his tool showed perfectly fine. However actual file downloads were still abysmally slow when connected to the ONT through the Merlin flashed AC68U.

This has me so confused, before enabling QoS that fateful night I would average about 750 megs down when downloading from my video production server, since then, it is impossible to go above 300kbps.
But I switched out the physical router and did not use any of the config files for the new one, they are not in any way linked other than running the same firmware. And QoS has never so much as been touched by this router, I only changed the subnet address and admin password and name and followed best practices as linked above.

This issue has 100% been narrowed down to the Merlin flashed router and nothing else.

And as the thread I first linked above has the exact same issue, I have to assume this is a bug somewhere that is forcing the QoS to be stuck on in some way and is linked to the attached machines.

I did notice when I was doing my offline autopsy on the old router a bit ago that I was able to enable QoS from a fresh install of Chrome and saw in there that the priorities were actually backward. The machines I had listed as the highest priority, were set as lowest. But that machine has now been wiped and will be going through extensive testing before being put back into the network.

Is it possible that when QoS is turned on it sets some sort of flag on the actually connected device itself telling it that it is unable to download? That is the only way I can think that the issue would persist through an actual hardware change.

Thank you all for any help or advice, at this point I am out of ideas and blaming it on spooky magic, the only time I have ever seen such issues is when QoS has been screwed up by someone not knowing what they were doing. And given that streaming video, gaming, and voice chat are all working fine, but web browsing and file downloads are impossibly slow, I have to assume it is QoS related.

Let's see if we can figure this out!

EDIT: I decided to do a test right now so we have a baseline.

Fast.com.
1637954870624.png


Testmy.net

1637954995988.png


Both tests were done in a Chrome incognito window with no extensions enabled and with default site settings.

Finally, a test of downloading a test SABnzbd file.

SABnzbd self-test results.
The download folder is on an SSD, completed folder is on spinning rust. Sab has been given 4GB of memory cache.

Results of trying to download the 1GB test file.

1637955324406.png



The same file with the VPN turned on using a fresh portable install of SAB on a different machine. If I turn the VPN off, the results are the same as above.


1637955602402.png
 

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A few random thoughts.

At this point, we need to ask, is this a converted RT-AC68U (i.e. a TM branded router)?

I don't see this as hardware-related, (if genuine), but that is a very old router today.

It really doesn't sound like you're properly resetting the router (at all).

Have you tried stock firmware?

Does this behave like this after fully resetting (possibly needs to be done multiple times on your device) using the appropriate instructions for your specific router below? Without connecting anything except one (test) device?

[Wireless] ASUS router Hard Factory Reset | Official Support | ASUS Global


Have you tried different browsers (without 'sticky' settings within), a different computer to flash the firmware with?

Anything installed on the setup computer that may be 'off'', and interfering with a proper clean setup?
 
The first one was a convert. The second one that I am running now however is an original.

And while they may be old, they have been very reliable for me for many years, very little in the way of issues, and just worked for the most part, minus being extremely susceptible to nearby lightning strikes taking out ports randomly.

I have gone through your best practices on resetting and will be doing so again with the original one once I confirm it is not a physical hardware issue with that machine. Then I will be testing it on the live network and seeing if the issue persists.

I did try the stock firmware, and I was reminded of just how abysmally slow it is lol. But the issue persisted through the stock firmware.

Yes, during my testing all other devices on the network were disconnected from the network. It went from ONT>AC68U>My Machine.

I used method 1 from that link to do the reset.

And yes, when setting up the second router while the first was still in use, I used a clean install of windows 10 on a development laptop to install the current version of Merlin and run the best practices. Firmware was installed with a fresh install of Chrome that was not logged in and not synced.

I can think of nothing on the setup computer that could be causing an issue.

I am about to work on the original router. It is a TM-AC1900 according to the badging. What would be your recommended steps to ensure a full and complete reset of the router?

I think the most puzzling thing to me is that I completely and totally removed the original hardware and replaced it with new hardware that shares no configuration files of any type. Further up until I touched the QoS settings this router gave me a consistent 1G+ down and 250M up for 6 years now.

This is so incredibly strange.

ONT>My Machine. Expected speeds.
ONT>AC68U>My machine. Degraded speeds.
ONT>Brand new AC68U>My Machine. Degraded speeds.
Brand new ONT>Brand new AC68U>My machine. Degraded speeds.

And I did try other machines as well as eliminating each link in the chain via switching out cables, removing switches, replacing them with known good ones, etc.

I have been troubleshooting this for 4 days now, and generally, I would think there has to be an issue with my network somewhere, but given that others over the years have experienced the exact same issue when touching the QoS setting I have to assume there is some sort of fundamental issue there.

The WAF of this network is quickly degrading and I need to get things back to standard, plus you know, work lol.

Feel free to toss out any ideas, I have the old router and a set of laptops sitting right behind me ready to be wiped and reinstalled and to update this router with as clean of an environment as humanly possible.

And thanks for all of the excellent help and advice you give around here, you are truly a treasure trove of info.
 
OK, so quick update.

I was able to confirm that the issue also appears with the direct connection to the ONT.

I called my ISP and they reprovisioned the ONT, which increased my speed to 9megs, still 991megs slower than I should be, but, better than 9kb lol.

They then rebooted the ONT, which again dropped me into the kb range.

Finally, I noticed the "on battery" light on the ONT was flashing, but there is no battery on this ONT so that seems like it may be a slight issue. It is flashing quickly and according to online documentation that means it is on battery but the battery is dying, but I confirmed it is actually on AC power and not a battery in sight, as well as unplugging it instantly turns it off.

They are coming out on the 30th to look into it.

Thank you for all your help, if there are any issues with the router, I will be back, but for now, it is rock steady, just dead damned slow. But that is not Merlin's fault.
 
The very long stories don't help to judge what is or was going on.
The basics are:
  1. Modified TM-AC1900's are not supported here.
  2. All speed tests shall at first be done with a wired connection, making sure the LAN ports and cabling do support the expected speed.
  3. Start the speed test directly at the ISP modem, if that meets the expected speed go to the next step.
  4. Setup your router from factory defaults with bare minimal settings (basically only: SSID's and passphrases) and make sure only ONE client (the one performing speed tests from) is connected during the tests.
  5. Test with a wired connection to the router, if that meets the expected speed go to the final step.
  6. Test with a wireless connection to the router, mind that for Gigabit speeds you need optimal conditions and wireless clients that support multiple data streams (very many do support only one stream, sometimes two streams). Some speed losses compared to wired are normal.
 
The very long stories don't help to judge what is or was going on.
The basics are:
  1. Modified TM-AC1900's are not supported here.
  2. All speed tests shall at first be done with a wired connection, making sure the LAN ports and cabling do support the expected speed.
  3. Start the speed test directly at the ISP modem, if that meets the expected speed go to the next step.
  4. Setup your router from factory defaults with bare minimal settings (basically only: SSID's and passphrases) and make sure only ONE client (the one performing speed tests from) is connected during the tests.
  5. Test with a wired connection to the router, if that meets the expected speed go to the final step.
  6. Test with a wireless connection to the router, mind that for Gigabit speeds you need optimal conditions and wireless clients that support multiple data streams (very many do support only one stream, sometimes two streams). Some speed losses compared to wired are normal.
1. The one I am asking about is not a modded one, it is an original.
2. They were, and they do.
3. Fiber To The Home does not have a modem.
4. I clearly stated that I did so.
5. I did.
6. You are not getting gigabit on a wireless connection. Even in ideal conditions unless in a lab.

This forum is filled with comments from senior members "you are not giving us enough to go on" "include more info" "how can we help you if you do not give us anything to go on".

So when I had an issue I gave the info that is generally asked for, issues, steps taken, results, screenshots, configuration information, testing parameters, and everything that less frequent and new users are generally scolded for not providing.

And then you respond, clearly not having read any of the content that I posted, and proceed to tell me I have screwed up by posting the exact info generally asked for.

Do you understand how absolutely confusing that can be for people?

After getting ahold of a senior tech at my ISP, a NOC tech came out today and we did some testing from my server room directly connected to the ONT and confirmed the issue is an upstream issue due to a misconfiguration on the customer update server that pushed out a bad set of updates to a large number of people, hence the sudden onset. It is looking like a failed QoS implementation in advance of a scheduled speed upgrade for my area.

The lead tech is coming in this evening to work on it and hopefully, we can get it fixed by Monday.

It is so disheartening to have taken the time to have put down the info asked for and still get scolded, and by someone who didn't even read the posts to ensure they were scolding me for something I had actually done wrong.
 
Using any QOS setting (and going back from it) may disable NAT Acceleration (CTF).
Yeah, that's why to ensure it was not a misconfiguration that was not being cleared I removed that machine and put in a completely different original AC68U to test. Settings show that both are enabled.

But I know now that the issue is with the ISP, not Merlin, it was purely coincidental.
 
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It is so disheartening to have taken the time to have put down the info asked for and still get scolded, and by someone who didn't even read the posts to ensure they were scolding me for something I had actually done wrong.

Speaking of myself, missteps are not uncommon... it's how we manage them that counts. You provided thorough and considered information on a tricky issue, made more tricky by the all too typical confluence of unrelated events... I did this and then that happened, by pointing to Asuswrt-Merlin, and by not ruling in the ISP sooner than later.

Sometimes too much information can distract from unfolding the troubleshooting process so as not to overlook the issue. But I think your purpose was served even if mostly by yourself by exploring the issue here and working the problem there. I say well done and don't mind any minor imperfections encountered along the way... they are a part of the process, such as it is.

Now about Senior Members... I think I made 10 posts here and was label a Senior Member... 20 posts and I became a piece of furniture. They are clearly fun titles without real meaning except maybe to encourage community in a common interest.

OE
 
Thank you, I appreciate this.

I think the most frustrating part of the entire troubleshooting process, was that before I did anything I immediately removed my entire network from the equation, hooked up my main machine to the ONT, and ran tests, they all passed, at which point I went back to working on the network.

It was not until the second time that I connected to the ONT alone that I saw it too was having the issue, though intermittently.

And this was the culprit for the start of the trouble on my end.

This is the ground lug on the incomming line.

1638155657517.png


And this is the power terminal block that provides power to the ONT. You can see the red and black wires going into it in the above image.

1638155712484.png


Note the burn marks on port 1 and 6?

Port one is power, but port 6 is "No Battery" when the system is hooked up to a UPS.

1638155784174.png


I have no idea how long that was arcing like that, or if it was a new occurance, but the original power connector was not removed when the previous tech replaced the ONT.

The connector itself had shorted pin 6 and it was intermittently firing off a no battery alarm and causing my system to go into emergency mode.

I just finished working with the on call tech, we got me abck up to 90 megs, but looks like there may be an issue with the demarc out at the end of my road.

So, we shall see.

And thank you again.
 
To be clear I did read or at least tried to read an understand what you wrote.
It is not a matter of scolding, it is a matter of narrowing down to valuable information and trying to take conclusions from there.
I have ran numerous times in situations where a client or who ever asks for help issues a large amount of information, but overlooked a detail that is crucial.
I wish you all the best an hopes your issues get fixed soon.
 
I think the most frustrating part of the entire troubleshooting process, was that before I did anything I immediately removed my entire network from the equation, hooked up my main machine to the ONT, and ran tests, they all passed, at which point I went back to working on the network.

Yeah, that's another tough one to detect.. intermittency. I just went through that with a dying AC86U 2.4 radio... sometimes clients connected, sometimes they did not. I chased the firmware... it's what we do most around here... until I made the observations that led to the correct conclusion.

Another one is cabling... interconnects... it's so fundamental yet frequently overlooked early on. When someone tells me they have an ISP issue, I inspect the cable from the demarc to their modem... eventually! So again, you found it...

Maybe... maybe there is still an issue at the street. That's another one... drawing premature/false conclusions can derail the troubleshooting process. I try to not do this for my own good. And I try to ignore this when done by others since it can get in the way of productive thinking. If you review your posts, you'll find many such branch decisions. This is normal... and something to be kept to a minimum. It is likely to present more frequently when there is too much information too soon... which can frustrate not only the process, but those wanting to pitch in and help from a distance.

Good troubleshooting is a bit of an art on top of knowledge. People good at it love it when they solve the tricky ones... and keep coming back for more... like the regulars on this forum. One trait they share is calm persistence... easier to do when it's not your own network that's down! So congrats... you may have been anxious but you are persisting and that is a most key ingredient to solving problems.

OE
 
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