Slow speed behind LAN, but fast speed if direct to WAN router - any idea why?

hardfire

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Latest update: Fixed. Problem due to bad CAT5e cable (which was branded and not self-made/crimped).
Or maybe what they wrote on the cable was not really CAT5e speeds.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Fiber ISP: ViewQwest

WAN Router: ASUS RT-AC88U (WAN mode)
Xjr20Cj.png


LAN (AP): ASUS RT-AC68U (AP mode)
H7Wa7AR.png


Speedtest: RT-AC88U --> PC
cSK49gl.png


Speedtest: RT-AC88U --> AC68U --> PC
tBHAH7q.png


Both routers/switch have latest firmware. All cables used are CAT 5E rated. No wireless connections. Just testing out the RT-AC68U as a kinda switch / access point for future expansion.

If I connect the PC directly to the WAN router, the speeds are much higher. Any experts can suggest what I did wrong? Is there a setting in the ASUS routers that I may have missed?
 
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hardfire

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The ASUS RT-AC68U is actually quite intelligent and auto configures itself into AP mode.

r6PwC2C.png
 
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kashix

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Shouldn’t have slow down. Can you try using CAT6 cable instead? I suspect bottleneck is the cable.
 

hardfire

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Shouldn’t have slow down. Can you try using CAT6 cable instead? I suspect bottleneck is the cable.

but I was using the same cables to direct connect the PC to the WAN router and I was getting Gbps speeds.
evidence:
cSK49gl.png


the only difference is putting the RT-AC68U as a LAN (switch) and connecting the PC to it. Then the test results drop to Mbps :(
 
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hk7310

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Could it be your cable connecting between your Asus router and ONT.

but I was using the same cables to direct connect the PC to the WAN router and I was getting Gbps speeds.

the only difference is putting the RT-AC68U as a LAN (switch) and connecting the PC to it. Then the test results drop to Mbps :(
 

hardfire

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Firmware updated ?

Push the reset button for 5-10 secs (until power LED blinks), then setup to AP (everything in auto settings, except wifi password) and try again ?

Also check the link speed in your asus AC88U under system status, is it 1Gbps or 100Mbps.

Ok I done the reset as instructed by the documentation. Holding the WPS and powering-off then powering-on the router. Then had to recreate login / password and wifi details again. Speeds are still the same.

How do I check the link speed? I assume I do it from the ASUS AC88U? or the AC68U? and which exact setting option do I check? I did try to find it in the asus router home pages but couldn't find anything.
 

hardfire

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Could it be your cable connecting between your Asus router and ONT.

No because prior to adding the AC68U modem I did a speed test and my setup was in the Gbps speed range.
evidence:
cSK49gl.png


Only after adding the AC68U, did I start getting the Mbps speeds.
 
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hardfire

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updated with evidence that when I connect PC directly to the AC88U, it's in the Gbps range.

So might be a router setting. But which router and what setting - that is the unknown. Was wondering if I should not use AP and manually set Routes?
 

xonix

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When you performed the test for pc to ac88, was it directly to ac88u lan port or you remove the cable from ac68 and plug it into pc ?
 

hardfire

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When you performed the test for pc to ac88, was it directly to ac88u lan port or you remove the cable from ac68 and plug it into pc ?
yes to both. AC88U -LAN-> PC was using the same cable as AC88U -LAN->AC68U config. The cable was the same.

But now it got me thinking - does it matter if it's a straight-through or crossover cable? These days are the routers/switches smart enough? And since I could get higher speeds when direct connect, I think all my cables are straight-through but how to check?

AC88U -> AC68U Or AC68U -> PC
Cable damaged?
Try ONT-> AC68U -> PC
Hmmm.. cables are fairly new, not super old. But as above, I wonder if straight or crossover cables matter. How to check?

I would like to try your suggestion for ONT -> AC68U -> PC but family is using the network last night and today as well, so I think they will complain to me so much LOL. Maybe when they are not home or something I try again.
 

hardfire

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Latest update: Fixed. Problem due to bad CAT5e cable (which was branded and not self-made/crimped).
Or maybe what they wrote on the cable was not really CAT5e speeds.

Experimented with the faulty CAT5e cable and found the network speeds to drop whenever I used it. I did a visual check on the RJ45 connectors and they look like straight through configuration yet not sure why the speeds dropped. I have put the cable aside and will now continue to connect rest of the home with better cables.
 
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