Another RT-AX86U Slow Speeds (<400mbs)

[VanJam]

My RT-AX86U is only putting through <400mbs.

I have centurylink fiber with a C4000BZ modem/router provided by them.

My entire system is hardwired with all new Cat6 cable. I tested each one directly out of the C4000BZ into my pc ethernet adapter and got 800-900mbs. Then c4000bz -> RT-AX86U -> pc and it drops to ~ 300mbs. Including everything down stream, wifi'd or hardlined.

I factory reset all asus routers and installed latest firmware. No change..

C4000BZ -> RT-AX86U -> RT-AX3000
-> RT-AX58U

All ethernet cable connections between everything.

Any suggestions are welcome. I see quite a few posts of people with the same issue but no solution.

 

[eibgrad]

A lot of these consumer-grade routers depend on some form of NAT acceleration to get near gigabit speeds. On my own RT-AC68U, it's an option under LAN->Switch Control. Don't recall if it is enabled by default (usually it is, but worth checking, if indeed you have that option).

 

[bbunge]

You may not need to use the Centurylink router. They incorrectly call a router a modem and in most of their installations they have an Optical Network Terminator (ONT) that the fiber connects to and there is an Ethernet cable between the ONT and the router. If this is the case with your installation, remove their router and plug the Ethernet cable directly into the WAN port of your router. The Asus router should get an internet connection and take off running. In some locations they use PPPoE connections will require you to do some additional configuration.
If this works and you are renting their router, send it back.
FYI: I am on Brightspeed FIOS, which used to be Centurylink.

Edit: I did not notice that you mentioned the model number of the modem/router. A C4000BZ which is a DSL Modem/router. If you truly have FIOS there is an Ethernet cable plugged into the WAN port of the C4000BZ. So, get rid of the C4000BZ and plug the Ethernet cable into the Asus.

 

[eibgrad]

P.S. I should add, sometimes the OEM does NOT have an explicit option for NAT acceleration, presumably to keep the GUI easier to understand and manage. In that case, enabling certain features may *silently* disable NAT acceleration because it is KNOWN to cause problems w/ those features. A classic example is QoS. Sometimes throughput analysis tools too. Could be other features as well. The OEM often doesn't tell you this outright because they don't want to provide you w/ the bad news.

All that said, I would presume a factory reset router would definitely have NAT acceleration enabled by default, if only to provide the user w/ the best performance out of the box. But just beware if could be disabled based on future changes.

 

[Tech9]

On my own RT-AC68U, it's an option under LAN->Switch Control.

None of the routers mentioned above have this setting. Used Runner/Archer/Flow Cache on this hardware is enabled by default unless something incompatible with it is selected on the main router. It can be as simple as Bandwidth Limiter on a Guest Network.

I factory reset all asus routers and installed latest firmware. No change..

Your main router configuration choices after factory reset may cause this WAN-LAN throughput restriction. Keep the default Asuswrt settings after factory reset, don't enable anything additionally including any of Trend Micro components. Test again and share the results.

 

[OzarkEdge]

I factory reset all asus routers and installed latest firmware. No change..

The reset is for the currently installed firmware, so be sure to Hard Reset the firmware before configuring it.

FW Reset FAQ

Reset button/webUI Restore/node removal clears settings in NVRAM; reboot restores fw defaults from CFE

Hard Reset via WPS button/webUI Restore+Initialize also clears data logged in /jffs partition

Perhaps you know this... but it's worth mentioning.

OE

 

[VanJam]

A lot of these consumer-grade routers depend on some form of NAT acceleration to get near gigabit speeds. On my own RT-AC68U, it's an option under LAN->Switch Control. Don't recall if it is enabled by default (usually it is, but worth checking, if indeed you have that option).

Doesn't look like I have that option.

 

[Tech9]

Doesn't look like I have that option.

Doesn't look like you read the posts above either.

 

[VanJam]

You may not need to use the Centurylink router. They incorrectly call a router a modem and in most of their installations they have an Optical Network Terminator (ONT) that the fiber connects to and there is an Ethernet cable between the ONT and the router. If this is the case with your installation, remove their router and plug the Ethernet cable directly into the WAN port of your router. The Asus router should get an internet connection and take off running. In some locations they use PPPoE connections will require you to do some additional configuration.
If this works and you are renting their router, send it back.
FYI: I am on Brightspeed FIOS, which used to be Centurylink.

Edit: I did not notice that you mentioned the model number of the modem/router. A C4000BZ which is a DSL Modem/router. If you truly have FIOS there is an Ethernet cable plugged into the WAN port of the C4000BZ. So, get rid of the C4000BZ and plug the Ethernet cable into the Asus.

I tried plugging directly into the ONT and it did not work.

How hard is the PPPoE connection configuration? (I'm a newb to networking) but decent at following directions. I looked up the directions on asus and it seems simple enough but also that I'll need to log into the pppoe on every device? Asus link I looked at

 

[VanJam]

Doesn't look like you read the posts above either.

Haha I was confirming that I don't have that option.

 

[VanJam]

None of the routers mentioned above have this setting. Used Runner/Archer/Flow Cache on this hardware is enabled by default unless something incompatible with it is selected on the main router. It can be as simple as Bandwidth Limiter on a Guest Network.



Your main router configuration choices after factory reset may cause this WAN-LAN throughput restriction. Keep the default Asuswrt settings after factory reset, don't enable anything additionally including any of Trend Micro components. Test again and share the results.

Sorry said that in the wrong order. I reset to factory after upgrading firmware. Only thing I changed was my SSID and split the signal into 2.4/5 G.

I can definitely try it again but that'll have to wait till next weekend when I'm home alone again.

 

[Tech9]

I can definitely try it again

Doing it twice is not needed. Wait for other suggestions.

 

[aex.perez]

I had something similar happen a while back, normally was geeting 900+ at the router and wired devices down stream. Then when I updated the firmware from 386.x to 388.x somehow somwhere Qos was enabled and some old settings got applied as well, took forever to figure out. But stumbled across the QoS setting, in the GUI as well as the packet prioritizaton settings. The moment I turned off QoS and blanked the settings, which survived a HW reset, and going back and forth between ASUSWRT and Merlin. The bandwidth shot back op to 900+ from 300-400. Even with QoS off, somehow the BWDPI engine was starting and using the packet prioritization settings, and once it did my Bandwith was cut in 1/2.

Evrytime I apply a firmware update, it's one of the things I check, as soon as the router settles down after the reboot (you'll see it, if it's off, under DataClassification), AiProtect has a similar impact.

 

[Tech9]

I had something similar happen a while back

Nothing you are talking about is enabled on stock firmware after factory reset. As I remember the issue you had was using unsupported custom scripts and hoping they’re okay even on new firmware base. scMerlin was causing your QoS confusion and perhaps retaining old settings.

 

[bbunge]

I tried plugging directly into the ONT and it did not work.

How hard is the PPPoE connection configuration? (I'm a newb to networking) but decent at following directions. I looked up the directions on asus and it seems simple enough but also that I'll need to log into the pppoe on every device? Asus link I looked at

You can get the PPoE or other WAN settings from the Centurylink router.

WAN settings

If instructed by a technician, you can change the protocol and addressing type on your modem, including PPPoE, IPoE or transparent bridging.

www.centurylink.com

Or call their tech support (good luck with that). Or do a chat with tech support to get the correct settings (user and password)

 

[Tech9]

How is bypassing the ISP router helping with the Asus throughput issue?

As far as I understand the ISP provided router has no throughput issues and the Asus is just a wired client in this case.

 

[dave14305]

login via ssh and run these commands to check the factors affecting acceleration:

fc status
nvram show 2>/dev/null | grep -E "^(fc|runner)_disable"
nvram get qos_enable
nvram get qos_type
nvram get rb_enable

 

[KevTech]

For Century Link you would need two things to use your own equipment.
1. PPoE username/password
2. Device needs to be able to do VLAN tagging 201.
I think you need 3.0.0.6 firmware to do VLAN tagging.

 

[Tech9]

I think you need 3.0.0.6 firmware to do VLAN tagging.

Perhaps this thing?

Available in all Asuswrt versions, but in a little unexpected place in LAN settings.

I still don't see how bypassing ISP device will fix Asus throughput issue. Something Century Link specific?

 

[aex.perez]

Nothing you are talking about is enabled on stock firmware after factory reset. As I remember the issue you had was using unsupported custom scripts and hoping they’re okay even on new firmware base. scMerlin was causing your QoS confusion and perhaps retaining old settings.

This was happening with stock Asuswrt and on Merlin, went back and forth a few times. Finally back on Merlin I found the setting exposed via SCMerlin And blanked all the settings, been fine ever since. It’s on the forum somewhere, just on my phone now but I can find it later…