RT-AC1900P in AP Mode Loses Wired LAN Connection Every 48-72 Hours

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New Around Here
We have an RT-AC1900P running Merlin 384.19 in AP mode. Every 48-72 hours, it loses its wired LAN connection. Connected WiFi clients lose internet and LAN access but stay connected and can access the web interface via its IP address. Anything connected to another AP or via Ethernet cannot reach the web interface. This makes me think the wired LAN interface is going down. A reboot fixes the issue for another 48-72 hours.

We have two other Asus routers, also in AP mode, and also running 384.19 that don't have this issue.

I'd welcome suggestions for how to troubleshoot or how and where I can post information to receive assistance.

Thank you!

EDIT: I searched a bit before posting and couldn't find anything that seemed similar.


Senior Member
What's on the other end of the uplink? I had a couple TPLINK (I think) 8 port Gb switches that didn't like ASUS AC-68 routers for some reason and when they decided to stop communicating I needed to power cycle one end or the other. I no longer use them.
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New Around Here
What's on the other end of the uplink? I had a couple TPLINK (I think) 8 port Gb switches that didn't like ASUS AC-68 routers...
EDITED because I realized our network layout had recently changed.

Hi there. Thanks for the question and for sharing your experience.

It turns out that the situation you encountered is the same as mine. The RT-AC1900P was previously connected directly to an old Cisco Catalyst switch and then pfSense. However, in setting things up for distance learning, an 8 port TP-Link switch was inserted between the RT-AC1900P and the Cisco switch.

The other Asus APs are connected directly to the Cisco switch and not misbehaving. I will adjust the cabling to bypass the TP-Link switch and report back. Thanks again.
Last edited:


New Around Here
Redoing the cabling to bypass either a TP-Link or Netgear unmanaged switch (I tried both) fixed this issue. Connecting the RT-AC1900P directly to the Cisco Catalyst managed switch, like our other Asus access points, works fine. It seems that the Asus router in AP mode did not like either unmanaged switch.

Thanks again, Smokindog!

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