AC87U Wired Speed Issues

[Ivan]

I have a strange issue with one of my AC87U routers. I am normally able to get 700-800Mbps via wired connection but very frequently the router will suddenly drop to 90Mbps. It takes a reboot to fix but the problem will always re-occur, sometimes within minutes or hours.

The problematic AC87U (blue) is bridged to another AC87U (red) via a 15m Cat7 flat profile cable. The red AC87U is connected to my ISP's ONT.

I've tried a factory reset and cold boot a few days ago but did not fix the issue (strangely the Internet LED was red the entire time).

I have currently swapped out the buggy AC87U with an older N66U. It's only a couple of hours but it seems to work well.

Is this due to a configuration issue with the AC87U, or is the router just faulty?

 

[hggomes]

Make sure you are not connected to LAN1 port (Realtek) on RT-AC87U, try LAN2,3 and 4 (Broadcom).

 

[Ivan]

Thanks - tried that - it worked for all of 5 minutes before it dropped the wired connection to my PC. Resetting the network adaptor didn't help, nor did a reboot of the PC and cycling power to the router.

It's just too damned unstable and I've had enough. If it can't be RMAed I'm going to take a sledgehammer to it for all the grief it's caused.

 

[hggomes]

No problem, you are welcome.

That seems extreme, even I can understand the frustration...

1. Have you tried different FW versions?
2. Have you tried a HW Reset + manual configuration from scratch?

 

[sfx2000]

Make sure you are not connected to LAN1 port (Realtek) on RT-AC87U, try LAN2,3 and 4 (Broadcom).

And make sure nothing is connected to LAN1 on that device....

Just repeating/clarifying things there...

Anything on 5G with the 87U, same thing...

 

[sfx2000]

15m Cat7 flat profile cable

No such thing - try a regular CAT5e cable...

 

[Martineau]

"Ivan said: ↑15m Cat7 flat profile cable"

No such thing - try a regular CAT5e cable...

Really?

I have several

https://www.amazon.co.uk/d/hvm/Ethe...=UTF8&qid=1496311525&sr=8-4&keywords=15m+cat7

running under carpets, keeps things neat and tidy.."other half" didn't even notice what I'd done!

 

[sfx2000]

Really?

I have several

https://www.amazon.co.uk/d/hvm/Ethe...=UTF8&qid=1496311525&sr=8-4&keywords=15m+cat7

running under carpets, keeps things neat and tidy.."other half" didn't even notice what I'd done!

CAT7 is not a recognized specification - CAT6a is the highest

So who knows what you actually have...

 

[Ivan]

Well the CAT7 flat cable works just as well as my previous CAT6a cable (which I thought was suspect and replaced). I'm pretty sure that wasn't the fault because the problems still persisted.

The situation hasn't changed after swapping out the blue AC87U with an older N66U. In fact, it's like nothing has changed at all. I still have to reboot both routers in order to get maximum bandwidth but it is promptly throttled to a meager 80~90Mbps within minutes. Occasionally the N66U will drop out complaining that the AC87U's "DHCP does not function" only to quickly recover. Accessing the AC87U's router web admin feels slow and unresponsive. Attempting to reboot it sometimes does nothing and has to be attempted repeatedly till it does.

Then I decided to replace the N66U out with a Linksys SE2500 unmanaged switch I had lying around. It's been a couple of hours and so far I am getting consistent wired speed from the AC87U. Speedtest results are consistent, as are downloads and test torrents. Browsing feels snappier.

Maybe these Asus routers are good by themselves but misbehave when bridged to one another?