Every now and then the Ethernet component of my RT-AX88U Pro seems to
seize up.
The WiFi side is still working and the Internet connection is still
working, but the local Ethernet connection on the back of the router seems
to stop for unexplained reasons.

Restarting the router doesn't always clear this.
Unplugging and re-plugging the connection to the in-house LAN doesn't
always clear this.
Connecting a PC directly to the LAN side of the router shows this doesn't
seem to be a fault with the in house LAN.

Unplugging the Ethernet connection(s) and then restarting seems to usually clear this, and moving the main LAN connection from 2.5 Gbits to 1 Gigabit port sometimes clears this but not consistently.

Has anyone else encountered a similar problem?

This is a fairly diverse LAN with TVs, Virgin Tivo, Humax satellite
decoders, a (blushes) power line adapter and various Windows and Android devices so picking one to blame is very difficult, and the fault is
infrequent enough to mean that any testing by eliminating connected
devices is not practical.

Internet search turns up Wifi problems but I haven't yet located anything specific to Ethernet.

Cheers



Dave R


--
W11 Home on Dell XPS 13 i7

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

David wrote:

[snip]

This is a fairly diverse LAN with TVs, Virgin Tivo, Humax satellite
decoders, a (blushes) power line adapter and various Windows and Android devices so picking one to blame is very difficult, and the fault is infrequent enough to mean that any testing by eliminating connected
devices is not practical.

Internet search turns up Wifi problems but I haven't yet located anything specific to Ethernet.

Presumably, with that many devices there is also a network switch.
Please therefore show us a network diagram like this:

Router port 1 = PC
Router port 2 = Network switch port 1 = TV1
............. = Network switch port 2 = TV2
............. = Network switch port 3 = Tivo
............. = Network switch port 4 = Humax
............. = Network switch port 5 = Power line adapter
etc ...

Please also tell us the make and model of the network switch.

Is any device (mis)configured so that it is trying to use Ethernet and
WiFi simultaneously?

When the Ethernet fails, can you see the router status using a PC that connects by WiFi? What does that tell you about the Ethernet ports, particularly speed, full/half duplex, auto-negotiation, etc?


--
Graham J

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On Thu, 22 Jan 2026 13:57:02 +0000, Graham J wrote:

David wrote:

[snip]

<snip>

When the Ethernet fails, can you see the router status using a PC that connects by WiFi? What does that tell you about the Ethernet ports, particularly speed, full/half duplex, auto-negotiation, etc?

The router status shows no devices connected via Ethernet.
I haven't seen a diagnostic which shows the status of the local ports on
the router, but will look.

Cheers



Dave R

--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 10 x64

--
This email has been checked for viruses by Avast antivirus software. www.avast.com

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On Thu, 22 Jan 2026 13:57:02 +0000, Graham J wrote:

<snip>

Please also tell us the make and model of the network switch.

<snip>

Network switch is TP-LINK TL-SG1016D Gigabit Switch.



--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 10 x64

--
This email has been checked for viruses by Avast antivirus software. www.avast.com

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On Thu, 22 Jan 2026 14:10:47 +0000, David wrote:

On Thu, 22 Jan 2026 13:57:02 +0000, Graham J wrote:

<snip>

Please also tell us the make and model of the network switch.

<snip>

Network switch is TP-LINK TL-SG1016D Gigabit Switch.

--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 10 x64

The switch is working, and all local devices are visible.
The fault is in the Ethernet ports on the router.



--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 10 x64

--
This email has been checked for viruses by Avast antivirus software. www.avast.com

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

David wrote:

On Thu, 22 Jan 2026 13:57:02 +0000, Graham J wrote:

<snip>

Please also tell us the make and model of the network switch.

<snip>

Network switch is TP-LINK TL-SG1016D Gigabit Switch.

Thanks. A network diagram would still help.

Can devices connected to the switch communicate with each other at the
time when the router ports appear to fail??


--
Graham J

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

David wrote:

On Thu, 22 Jan 2026 14:10:47 +0000, David wrote:

On Thu, 22 Jan 2026 13:57:02 +0000, Graham J wrote:

<snip>

Please also tell us the make and model of the network switch.

<snip>

Network switch is TP-LINK TL-SG1016D Gigabit Switch.

The switch is working, and all local devices are visible.
The fault is in the Ethernet ports on the router.

How have you proved that?

Have you a different router you can try?


--
Graham J

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On Thu, 22 Jan 2026 17:26:23 +0000, Graham J wrote:

David wrote:

On Thu, 22 Jan 2026 13:57:02 +0000, Graham J wrote:

<snip>

Please also tell us the make and model of the network switch.

<snip>

Network switch is TP-LINK TL-SG1016D Gigabit Switch.

Thanks. A network diagram would still help.

Can devices connected to the switch communicate with each other at the
time when the router ports appear to fail??

Yes.
Please read the original post?

Internal network through the TP-Link switch seems to be working.

Ethernet component of the router is not working.
No connection shown by router for the LAN.
When working, active Ethernet connections are listed.
Ports on router tested using local laptop and shown to be non-functional.

At the moment I am failing to see what value spending an hour or more producing an up to date network map would add to the conversation.
The fault is already tied down to the Ethernet side of the router.
The router itself is working and still carrying WiFi traffic to and from
the Internet.

I am asking for anyone who has experienced a similar fault.

Cheers


Dave R

--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 10 x64

--
This email has been checked for viruses by Avast antivirus software. www.avast.com

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On Thu, 22 Jan 2026 15:52:32 +0000, Andy Burns wrote:

David wrote:

Every now and then the Ethernet component of my RT-AX88U Pro seems to
seize up.

Presume you've checked for any firmware update for it?#

It auto updates and firmware is the latest available.



--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 10 x64

--
This email has been checked for viruses by Avast antivirus software. www.avast.com

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On Thu, 22 Jan 2026 13:57:02 +0000, Graham J wrote:

David wrote:

[snip]

This is a fairly diverse LAN with TVs, Virgin Tivo, Humax satellite
decoders, a (blushes) power line adapter and various Windows and
Android devices so picking one to blame is very difficult, and the
fault is infrequent enough to mean that any testing by eliminating
connected devices is not practical.

Internet search turns up Wifi problems but I haven't yet located
anything specific to Ethernet.

<snip>

Is any device (mis)configured so that it is trying to use Ethernet and
WiFi simultaneously?

<snip>

I have checked and for Windows devices this is not a mis-configuration.
There is scope for additional configuration for specialist needs but as standard Windows defaults to using the fastest link.

Cheers



Dave R

--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 10 x64

--
This email has been checked for viruses by Avast antivirus software. www.avast.com

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

David wrote:

[snip]

Internal network through the TP-Link switch seems to be working.

Ethernet component of the router is not working.
No connection shown by router for the LAN.
When working, active Ethernet connections are listed.
Ports on router tested using local laptop and shown to be non-functional. > At the moment I am failing to see what value spending an hour or more producing an up to date network map would add to the conversation. > The fault is already tied down to the Ethernet side of the router.
The router itself is working and still carrying WiFi traffic to and from
the Internet.

I am asking for anyone who has experienced a similar fault.

I have seen a similar but permanent fault on a router. Several years
ago, can't remember the make or model.

I think you've proved that your router is faulty. The final check would
be to try another router. If that shows the same fault then we really
will need a good network map.

When and where did you buy the router? Is it still under warranty?

If not under warranty you will just have to buy another. Perhaps one
from a different manufacturer ...?

--
Graham J

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

On 22/01/2026 13:04, David wrote:

Every now and then the Ethernet component of my RT-AX88U Pro seems to
seize up.
The WiFi side is still working and the Internet connection is still
working, but the local Ethernet connection on the back of the router seems
to stop for unexplained reasons.

Restarting the router doesn't always clear this.
Unplugging and re-plugging the connection to the in-house LAN doesn't
always clear this.
Connecting a PC directly to the LAN side of the router shows this doesn't seem to be a fault with the in house LAN.

Unplugging the Ethernet connection(s) and then restarting seems to usually clear this, and moving the main LAN connection from 2.5 Gbits to 1 Gigabit port sometimes clears this but not consistently.

Has anyone else encountered a similar problem?

This is a fairly diverse LAN with TVs, Virgin Tivo, Humax satellite
decoders, a (blushes) power line adapter and various Windows and Android devices so picking one to blame is very difficult, and the fault is infrequent enough to mean that any testing by eliminating connected
devices is not practical.

Internet search turns up Wifi problems but I haven't yet located anything specific to Ethernet.

Happened to a router of mine quite a few years ago. Can't remember the
brand.
The first ethernet port went dead followed by the second some weeks
later. It was put down to the cheap faulty capacitors that flooded the
market. Some of these may still be about & being used by various manufacturers.



--
Regards
wasbit

--- PyGate Linux v1.5.2
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)