ASUS RT-AC88U obtains internet connection for ~1 second then connection drops

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Peanut

Occasional Visitor
Hi,

I have an ASUS RT-AC88U running Asuswrt-Merlin firmware (version 386.2_4 at time of failure) it had been running without issue ~2 years (well there have been constant dropouts the past few months but connection is always res-established) but on Friday morning my internet connection dropped out - I connected up my ISP router and connected successfully so I performed the following steps:

1. Restored to factory settings, loaded known to be good config file - internet connection established then dropped after about 1 second

2. Restored to factory settings, manually configured connection - internet connection established then dropped after about 1 second

3. Loaded Asuswrt-Merlin version 386.1_0, restored to factory settings, manually configured connection - internet connection established then dropped after about 1 second

4. Loaded ASUS FW 3.0.0.4.386.41700, manually configured connection - internet connection established then dropped after about 1 second

5. Loaded Asuswrt-Merlin version 384.19_0 (as I had a known to be good config backup), restored config - internet connection established then dropped after about 1 second

6. Installed Asuswrt-Merlin version 386.2_4, restored to factory settings, manually configured connection and configured DUAL WAN with Ethernet LAN 2 acting as primary internet connection - no connection established.

If I leave the device sitting connected to the ONT the connection is established, an IP address is assigned from my ISP then the connection immediately drops, it goes through a connection and disconnection loop.


I stupidly did not obtain logs from the device before I reset but have since saved logs which show the connects/disconnects.

My ISP (Sky Ireland) have stated there has been no change on their end...


Apologies about the long post but can anyone help please?


Logs: https://1drv.ms/t/s!AsMiGK22s5rIoxDOmFPGtgERmHQB?e=nQFHPg
 
Last edited:

royarcher

Very Senior Member
Hi,

I have an ASUS RT-AC88U running Asuswrt-Merlin firmware (version 386.2_4 at time of failure) it had been running without issue ~2 years (well there have been constant dropouts the past few months but connection is always res-established) but on Friday morning my internet connection dropped out - I connected up my ISP router and connected successfully so I performed the following steps:

1. Restored to factory settings, loaded known to be good config file - internet connection established then dropped after about 1 second

2. Restored to factory settings, manually configured connection - internet connection established then dropped after about 1 second

3. Loaded Asuswrt-Merlin version 386.1_0, restored to factory settings, manually configured connection - internet connection established then dropped after about 1 second

4. Loaded ASUS FW 3.0.0.4.386.41700, manually configured connection - internet connection established then dropped after about 1 second

5. Loaded Asuswrt-Merlin version 384.19_0 (as I had a known to be good config backup), restored config - internet connection established then dropped after about 1 second

6. Installed Asuswrt-Merlin version 386.2_4, restored to factory settings, manually configured connection and configured DUAL WAN with Ethernet LAN 2 acting as primary internet connection - no connection established.

If I leave the device sitting connected to the ONT the connection is established, an IP address is assigned from my ISP then the connection immediately drops, it goes through a connection and disconnection loop.


I stupidly did not obtain logs from the device before I reset but have since saved logs which show the connects/disconnects.

My ISP (Sky Ireland) have stated there has been no change on their end...


Apologies about the long post but can anyone help please?


Attached logs.
How old is the RT 88 U ? What sort of temperatures is it subjected to?
 

Peanut

Occasional Visitor
How old is the RT 88 U ? What sort of temperatures is it subjected to?
Production year is 2017 but I only purchased it in Feb 2019.
Temps are usually 57 deg Celsius - I have placed fans on it in the past but they did not affect the temperature of the device.
 

Peanut

Occasional Visitor
Your issue sounds like this one although I don't think there was a solution found.

Or possibly this: http://www.snbforums.com/threads/asuswrt-merlin-386-2-is-now-available.71625/post-679251 Are you using guest WiFi networks?
Thanks for the suggestions - I have tried a couple of the older builds thinking it may be a firmware issue and even tried the ASUS stock firmware but the issue persists on all.
At the time the issue presented itself, yes I was using a Guest wifi but since I've been resetting the device and uploading different firmware versions I have not configured a Guest network as I just wanted to test the internet connection.
 

L&LD

Part of the Furniture
Try the following to see if it is a hardware issue (as much as we can tell by observation). Forget testing older builds. Even if it somehow works, the results mean little when security is a priority also.

Fully Reset Router and Network

Test with new, never before used, SSIDs. Test with different WAN cables. Test with different cable Brands, not just CatXx labels. Remove all USB attached devices. Remove all LAN cables. Do not use any saved backup config files. Do not re-attach anything before determining that the router is defective (or not).

Do not 'blindly' put in old settings that may have worked long ago.

If the router is stable with a single wireless client device for an extended period, perform the following and then afterward, slowly add your client devices one by one to determine if any of them are responsible for the symptoms.

Best Practice Update/Setup Router/AiMesh Node(s) 2021
 

Peanut

Occasional Visitor
Try the following to see if it is a hardware issue (as much as we can tell by observation). Forget testing older builds. Even if it somehow works, the results mean little when security is a priority also.

Fully Reset Router and Network

Test with new, never before used, SSIDs. Test with different WAN cables. Test with different cable Brands, not just CatXx labels. Remove all USB attached devices. Remove all LAN cables. Do not use any saved backup config files. Do not re-attach anything before determining that the router is defective (or not).

Do not 'blindly' put in old settings that may have worked long ago.

If the router is stable with a single wireless client device for an extended period, perform the following and then afterward, slowly add your client devices one by one to determine if any of them are responsible for the symptoms.

Best Practice Update/Setup Router/AiMesh Node(s) 2021
Hi, yes, I forgot to mention I had tried multiple different cables (including one thats works with my ISP router),reset the ONT device and configured different wireless connections details - I do not have anything but the WAN connection connected to the router but the internet connection still constantly drop after 1 second of being established. I have loaded the most current firmware, reset and manually input the connection details but the issue persists.
 

Peanut

Occasional Visitor
Is the ISP device a modem only or a modem/router? Any chance to let their own device establish the connection?
ISP device is a router and connects without issue - its what I have had to resort to using at the moment unfortunately.
 

L&LD

Part of the Furniture
Are you able to Bridge their modem/router and use your router instead?
 

Tech9

Very Senior Member
ISP device is a router and connects without issue - its what I have had to resort to using at the moment unfortunately.

Let the ISP router establish the connection, double NAT yours, place it in DMZ and don't worry about it too much.
 

Peanut

Occasional Visitor
Let the ISP router establish the connection, double NAT yours, place it in DMZ and don't worry about it too much.
I have tried the following (but may/must be missing a step) - I have connected the ONT device to the WAN port on my ISP router, disabled WiFi and DHCP on ISP router, configured a static IP on the ASUS in the same range as the ISP router, configured the static IP address of the ASUS in the DMZ on the ISP router and connected from a LAN port on my ISP router to the WAN port on the ASUS but I am still receiving the same error.
Can you advise on what I am missing please?
 

ColinTaylor

Part of the Furniture
... but I am still receiving the same error.
I assume you're talking about the pppd errors? In the setup you have now the Asus' WAN Connection Type should be configured as Automatic IP (or Static IP) not PPPoE.
 
Last edited:

Tech9

Very Senior Member
Can you advise

I would try it other way. Leave DHCP on the ISP router enabled, disable Wi-Fi. Set your Asus router with automatic WAN IP. This should work with no issues, test it. If successful, reserve on the ISP router an IP address for your Asus router, place this address in DMZ.
 

Peanut

Occasional Visitor
I would try it other way. Leave DHCP on the ISP router enabled, disable Wi-Fi. Set your Asus router with automatic WAN IP. This should work with no issues, test it. If successful, reserve on the ISP router an IP address for your Asus router, place this address in DMZ.
Thank you, I'll try it - I did have the connection type set to Automatic but maybe just did too much before testing.
 

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