RT-AC88U drops the same 2 users with no warning every few days

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MameShiba

Occasional Visitor
Config:
RT-AC88U
Asuswrt-Merlin V 384.19

Backstory:
Before I switched to Merlin my router would randomly drop all wired connections at seemingly random intervals without any error messages, warnings or any way to fix it without restarting the router.
This behavior completely stopped after switching to Merlin now a few months of using it a new problem arrives.
Issue:
Since about 2 weeks now every few days the connection to the internet on 2 specific users would be cut at the exact same time, meanwhile it would still work for everyone else, no matter what I tried in the settings it wouldn't work and from what I could understand from the logs I couldn't make out the issue.
The 2 users have nothing special in common that the other users who keep working as intended don't have. The only way I managed to fixed it is by turning off the router, waiting at least a few minutes and then turning it back on again. If I don't wait long enough the problem persists. I have switched around which port on the router the ethernet cables lead into which changed nothing and switching out the cables themselves isn't easily possible at the moment.

Any help would be kindly appreciated and if any info is needed I'll gladly provide it.
 

QuikSilver

Very Senior Member
Config:
RT-AC88U
Asuswrt-Merlin V 384.19

Backstory:
Before I switched to Merlin my router would randomly drop all wired connections at seemingly random intervals without any error messages, warnings or any way to fix it without restarting the router.
This behavior completely stopped after switching to Merlin now a few months of using it a new problem arrives.
Issue:
Since about 2 weeks now every few days the connection to the internet on 2 specific users would be cut at the exact same time, meanwhile it would still work for everyone else, no matter what I tried in the settings it wouldn't work and from what I could understand from the logs I couldn't make out the issue.
The 2 users have nothing special in common that the other users who keep working as intended don't have. The only way I managed to fixed it is by turning off the router, waiting at least a few minutes and then turning it back on again. If I don't wait long enough the problem persists. I have switched around which port on the router the ethernet cables lead into which changed nothing and switching out the cables themselves isn't easily possible at the moment.

Any help would be kindly appreciated and if any info is needed I'll gladly provide it.
What do the logs show? That should help shed more light on it. There has to be something around that time during this if router is at fault I would think. Uploading the logs for others to look at would be beneficial in tracking it down for you.
 

MameShiba

Occasional Visitor
This is the syslog I just pulled off the router, happened again today at around 14 o' clock.
The logs only start at 14 for the day to begin with, I have no clue why that is but I'm guessing the restart is at fault?
 

Attachments

  • syslog.txt
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sbsnb

Senior Member
Is it your LG device that's having the problem after a reboot?
 

MameShiba

Occasional Visitor
Nope, both of the devices being dropped are Windows 10 PC's all the IPV4 properties on every pc in the network are set to "Obtain Automatically" that includes the devices that get dropped and those that don't.
All of the PC's are connected via ethernet btw
 

sbsnb

Senior Member
Are they set to use a random MAC address?

 

MameShiba

Occasional Visitor
They are both wired up to the router and have no wi-fi built into their motherboards nor a wi-fi card installed so neither of them have the option to turn that off or on available
 

sbsnb

Senior Member
What is the indication that they are dropped? The router doesn't show them in the client list (known issue), those devices have no LAN access, etc.?
 

MameShiba

Occasional Visitor
Yeah they disappear from the client list and in the windows 10 interface they are shown as being "connected to the network" but without internet access, I haven't checked if the two devices can actually retain any network functionality
 

sbsnb

Senior Member
See if you can ping the router and other devices on the LAN. I see my wired devices disappear from the client list all the time.
 

MameShiba

Occasional Visitor
If they would just disappear that wouldn't be much of a problem but the internet not working anymore is, since it makes me unable to work from home when it does happen.
Another thing I noticed is that when it does happen the IPV4 address you can find under "ipconfig" in the cmd changes to a random address that isn't anywhere near the ip range of our DHCP server
 

MameShiba

Occasional Visitor
I have tried forcing the devices to adopt a valid IP in the adapter options with and without also assigning the MAC address that static IP which even after restarting the device seems to have not worked, and even if I set up the static IP in advance that will still happen
 

sbsnb

Senior Member
How is your subnet mask set in your router and in your PCs? Is it just the typical 255.255.255.0?
 

MameShiba

Occasional Visitor
On the devices its set to auto, the router uses tripple 255, When I was trying static IP I did set the subnet mask as the same as on the router
 

sbsnb

Senior Member
That means the devices are loosing their IP configuration and not renewing them for whatever reason. If other devices on the LAN are not experiencing similar issues that rules out an issue with the router's DHCP server or access thereto. That leaves a problem on the client, the wiring, the Ethernet ports, or the data path from the Ethernet ports. My money's on the network configuration of the clients, but other things are possible.

Can you try moving the affected clients from one group of LAN ports to the other (e.g., 1-4 to 5-8, or vice versa).
 

MameShiba

Occasional Visitor
One time it happened I did try changing the ports around on the router but I only switched them inside the 5-8 port range are the 2 groups that important?
 

L&LD

Part of the Furniture
Yes they are. Ports 1-4 are separate from the Ports 5-8 (internally).
 

MameShiba

Occasional Visitor
So the issue might be that the router has a problem with the latter group of ports? Would there be a way to fix this if that's the case?
 

sbsnb

Senior Member
There's always a way to fix a problem, but first we have to identify the problem. Switching port groups can tell us something about the issue. If the problem goes away we can focus on some internal router issue with the port group. If the issue doesn't go away I would suggest downloading a Linux or BSD distribution that can run from a live CD or USB drive and boot one of those machines on that to see if the problem remains. That will tell us if it's a Windows problem.
 

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