Slow wired up-link and lower WAN throughput from router than from connected devices

[Quentin]

I have an ASUS RT-AC3100 running Merlin 384.10_2. My internet service was recently upgraded to symmetrical Gigabit fiber.

When I connect my laptop directly to the incoming Ethernet link from the fiber switch, I measure throughput of around 930 Mbps up and down.

When I connect the link to the Asus router WAN port and my laptop to a LAN port, I still get 930 Mbps down, but only 250 Mbps up.

In an attempt to debug the issue, I installed the Entware speedtest-cli package. Running speedtest on the router results in only 300 Mbs down and 210 Mbs up!

Any ideas around (a) possible reasons for the slow uplink speed and (b) why the speed as measured from the device is lower than through a LAN port?

 

[L&LD]

I have an ASUS RT-AC3100 running Merlin 384.10_2. My internet service was recently upgraded to symmetrical Gigabit fiber.

When I connect my laptop directly to the incoming Ethernet link from the fiber switch, I measure throughput of around 930 Mbps up and down.

When I connect the link to the Asus router WAN port and my laptop to a LAN port, I still get 930 Mbps down, but only 250 Mbps up.

In an attempt to debug the issue, I installed the Entware speedtest-cli package. Running speedtest on the router results in only 300 Mbs down and 210 Mbs up!

Any ideas around (a) possible reasons for the slow uplink speed and (b) why the speed as measured from the device is lower than through a LAN port?

The router does not have enough RAM or CPU power to speedtest at 1Gbps speeds. This is normal and par for the course.

Any reason you're running an older RMerlin version? v384.11_2 is recommended and 384.12 Alpha 1 g4a8cd4ead5 is also extremely stable for many, including myself.

https://asuswrt.lostrealm.ca/download

Click on the 'pre-beta builds' in the link above for the Alpha firmware.

Do you have QoS running on your router? If you do, disable it. As 1Gbps ISP levels don't require it and also force your router to lower speeds when hardware acceleration isn't used (by about 1/4 to 1/3 of Gbps levels).

If that isn't the issue and you have hardware acceleration working and enabled, then the following steps may help.

Try turning off your ONT, your router and any other switches you may have connected in your network. Leave the devices off for at least 10 minutes (30 minutes or more is better) and then power on the ONT, wait 5 minutes, power on the router, wait another 5 minutes and then power on any other switches installed.

If the issues persist at this point, I would recommend a full reset to factory defaults followed by a minimal and manual configuration (do not use a saved backup config file) to secure your router and connect to your ISP.

The M&M Config guide in my signature below may be useful to follow and help you get your router to a good/known state as quickly as possible.

 

[Quentin]

Thank you for the detailed response. I do not have QoS running, nor any other services. The older firmware version is not installed for any particular reason; it has just been a while since I updated. Will be sure to update first thing, and will also try the reset sequence you suggested if that does not work.

The router does not have enough RAM or CPU power to speedtest at 1Gbps speeds. This is normal and par for the course.


Any reason you're running an older RMerlin version? v384.11_2 is recommended and 384.12 Alpha 1 g4a8cd4ead5 is also extremely stable for many, including myself.

https://asuswrt.lostrealm.ca/download

Click on the 'pre-beta builds' in the link above for the Alpha firmware.

Do you have QoS running on your router? If you do, disable it. As 1Gbps ISP levels don't require it and also force your router to lower speeds when hardware acceleration isn't used (by about 1/4 to 1/3 of Gbps levels).

If that isn't the issue and you have hardware acceleration working and enabled, then the following steps may help.

Try turning off your ONT, your router and any other switches you may have connected in your network. Leave the devices off for at least 10 minutes (30 minutes or more is better) and then power on the ONT, wait 5 minutes, power on the router, wait another 5 minutes and then power on any other switches installed.

If the issues persist at this point, I would recommend a full reset to factory defaults followed by a minimal and manual configuration (do not use a saved backup config file) to secure your router and connect to your ISP.

The M&M Config guide in my signature below may be useful to follow and help you get your router to a good/known state as quickly as possible.

 

[Quentin]

Just wanted to report back in case someone else has the same problem. I upgraded the firmware, powered down everything then followed the power on sequence you described and now I am getting full symmetrical up/down speed.

The router does not have enough RAM or CPU power to speedtest at 1Gbps speeds. This is normal and par for the course.

Any reason you're running an older RMerlin version? v384.11_2 is recommended and 384.12 Alpha 1 g4a8cd4ead5 is also extremely stable for many, including myself.

https://asuswrt.lostrealm.ca/download

Click on the 'pre-beta builds' in the link above for the Alpha firmware.

Do you have QoS running on your router? If you do, disable it. As 1Gbps ISP levels don't require it and also force your router to lower speeds when hardware acceleration isn't used (by about 1/4 to 1/3 of Gbps levels).

If that isn't the issue and you have hardware acceleration working and enabled, then the following steps may help.

Try turning off your ONT, your router and any other switches you may have connected in your network. Leave the devices off for at least 10 minutes (30 minutes or more is better) and then power on the ONT, wait 5 minutes, power on the router, wait another 5 minutes and then power on any other switches installed.

If the issues persist at this point, I would recommend a full reset to factory defaults followed by a minimal and manual configuration (do not use a saved backup config file) to secure your router and connect to your ISP.

The M&M Config guide in my signature below may be useful to follow and help you get your router to a good/known state as quickly as possible.

 

[TechBuddy]

Just wanted to report back in case someone else has the same problem. I upgraded the firmware, powered down everything then followed the power on sequence you described and now I am getting full symmetrical up/down speed.

I recently ran into the same problem, during my troubleshooting I found the issue was linked to a couple settings but what triggered it was enabling the bandwidth limiter for my open wifi network
Once this was enabled it modified my NAT acceleration "Auto" setting to CPU load acceleration.

Turning off the bandwidth limiter and going into the LAN-->Switch Control Clicking Apply to reapply the Jumbo Packet, NAT Acceleration setting, and LAG settings. The switch auto restarted/reloaded and NAT acceleration switched to CTF (Cut Through Forwarding) and my speeds returned to normal again

with NAT Acceleration on Auto and the device selecting CPU load acceleration I was getting 250-~300/310 mbps, but I wasn't seeing anywhere near the 480mbps I was getting from a direct modem link test