Weird Network Behaviour with LAN Port 1 on AC87U

[bitoiu]

Hi friends,

I've owned an AC87U for almost 2 years now, and for the most part it has been a great experience, other than the 5G starting to drop about a year ago. However, since I don't want to change just now to a Wifi 6 router based on the posts I read on snb.com I've been trying to deal with it.

The latest issue I've got (and I've seen related posts on this forum) is with LAN Port 1. The Port doesn't totally fail which is why I'm trying to understand if this could be miss configuration. I've detected a problem yesterday where my Chromecast Ultra was complaining about no connectivity. I found that odd because it's wired to Lan Port 1. I did a quick shift of Ports 1 and 2 and suddenly the Chromecast came to life. I did restart the router as well and that hid the problems I would see later last night.

So now on Lan Port 1 I have my mac mini server running Plex, Sonarr, Radarr, Torrents, etc. Starting last night I couldn't connect to any service using either the IP or the Static IP hostname (mac-mini). I can however connect to the host using the DDNS entry that I use to connect to it from the outside. The host itself has a WAN connection because I can still stream plex (indirectly).

To try and find where the problem is I validated the following:
- Tried hitting the host from several clients, all fail using IP or hostname
- If I run a nslookup to the network IP, it resolves to the hostname set on the DHCP settings on the router
- I don't have a VPN configured in the router at the moment.
- I'm running the latest Merlin software.
- As soon as I connect the mac-mini to Lan Port 2, it works all as expected.

Below are some of my settings that might help with assistance, thank you in advance

 

[bitoiu]

Correction: after a few hours after changing from Port 1 to Port 2, the same issue again. Can't SSH, HTTP, or share screen with the mac-mini host at all. Change Port 1 and Port 2 cables everything working again.

In a few hours I'll loose connectivity to the device on 192.168.1.23/

I'm out of ideas....

 

[OzarkEdge]

Correction: after a few hours after changing from Port 1 to Port 2, the same issue again. Can't SSH, HTTP, or share screen with the mac-mini host at all.

I'm out of ideas....

I would... swap in your old/backup router. If the problem goes away, reset and reconfigure from scratch your suspect router. If the problem persists and considering your router WiFi is failing, replace the router.

Online advice is cheap!

OE

 

[bitoiu]

I would... swap in your old/backup router. If the problem goes away, reset and reconfigure from scratch your suspect router. If the problem persists and considering your router WiFi is failing, replace the router.

Online advice is cheap!

OE

Hi OzarkEdge

Thank you for the reply.

> I would... swap in your old/backup router.

I don't have one

> If the problem goes away, reset and reconfigure from scratch your suspect router.

I'm going to do a full factory reset tomorrow, update to latest stock, and then upgrade to latest merlin.

> considering your router WiFi is failing, replace the router.

I feel this is the case, just waiting until wifi-6 routers get a bit more mature.

Thank you.

 

[L&LD]

@bitoiu, a full factory reset is needed after flashing the firmware, not before (although it won't hurt to do it before too).

A full reset to factory defaults is also needed after flashing RMerlin firmware onto the router too. I would recommend that you flash RMerlin firmware, reset to factory defaults, do a quick/temporary set up and then reflash the same RMerlin firmware once again and then do a full and proper minimal and manual set up.

Please see my signature below to the M&M Config and Nuclear Reset guides for further details on getting your router back to a good/known state.

 

[bitoiu]

@bitoiu, a full factory reset is needed after flashing the firmware, not before (although it won't hurt to do it before too).

A full reset to factory defaults is also needed after flashing RMerlin firmware onto the router too. I would recommend that you flash RMerlin firmware, reset to factory defaults, do a quick/temporary set up and then reflash the same RMerlin firmware once again and then do a full and proper minimal and manual set up.

Please see my signature below to the M&M Config and Nuclear Reset guides for further details on getting your router back to a good/known state.

L&LD, I've spent 30 min today searching for a "AC87U reset guide" both on the forum search and google (searching the forum), to the link you precisely provided. I've read through it and it was just what I was looking for. I've come across a few of these but I never bookmarked them before. I've just noticed that the M&M guide was one of the ones I've seen before and was trying to find again. If you didn't link this, I wouldn't have done factory reset after merlin flashing.

This just removed a ton of anxiety from the formatting and now I also have the M&M guide. If I may I have two questions for you:

> Before you go customizing the router any further, I would recommend following the beginning part of the amtm Step-by-Step guide to have a spare USB drive properly formatted, and used with a swap file. Do not add any other scripts yet through amtm until the router has proved stable to this point.

1. I've read amtm guide and for the time being I haven't had the need for custom scripts. Do you still recommend I do this?
2. How happy are you with the ax88u? I think my ac87u is breaking and that's my contender.

Thank you L&LD

 

[L&LD]

@bitoiu, thank you for the kind words.

1) I do recommend to install amtm, the disk checker and a swap file for any RMerlin supported router that you have a spare USB drive for.

2) I am very happy with it. In the same signature link, look at the bottom for the 'RT-AX88U Upgrade' link to see how much it improves my network over the RT-AC86U I had previously (a great router too, BTW).

With the limited resources current routers have, having a swap file is very beneficial (I always use and recommend the maximum, 2GB size on an Ext4 partition with journaling enabled). To get the most from the USB, use a quality USB extension cord if you have one laying about. It keeps the USB drive from heating up the router too.

 

[OzarkEdge]

Hi OzarkEdge

Thank you for the reply.

> I would... swap in your old/backup router.

I don't have one

> If the problem goes away, reset and reconfigure from scratch your suspect router.

I'm going to do a full factory reset tomorrow, update to latest stock, and then upgrade to latest merlin.

> considering your router WiFi is failing, replace the router.

I feel this is the case, just waiting until wifi-6 routers get a bit more mature.

Thank you.

This FAQ explains the factory default reset.

I discovered a similar requirement recently when resetting some Android mobiles. They needed to be reset and updated twice! The first reset/update appears to affect the outcome of the second reset/update... you get a different/more updated installation after the second reset/update.

OE

 

[bitoiu]

1) I do recommend to install amtm, the disk checker and a swap file for any RMerlin supported router that you have a spare USB drive for.

I'll do 1) then, I'll get the reading in before I'm in the middle of it. This is a new part of the configuration a bit alien to me.

2) I am very happy with it. In the same signature link, look at the bottom for the 'RT-AX88U Upgrade' link to see how much it improves my network over the RT-AC86U I had previously (a great router too, BTW).

I thought when I first chased that link I got your default settings for MIMO, but I must have chased the wrong link. If my router continues with the 5Ghz and local network issues, then I'm sold

> This FAQ explains the factory default reset.

Thank you @OzarkEdge, I will add this to my list and pair it with the Nuclear reset @L&LD provided.

You guys were very helpful, thank you.

 

[bitoiu]

I've done the Nuclear Reset, amtm swap installation (and I've started using the spdMerlin as a test to get my feet wet). I'm just about to finish the M&M settings, and I'm going to leave it at that for a week or so. Then I'll change frequency and channels for WiFi. After that I'll do Port Forwarding etc. @L&LD because I kind of need to get port forwarding going to my server, do you see this as a type of change that I should be careful and slowly rolling out. Or this is mainly for the WiFi settings?

Thank you @L&LD and @OzarkEdge.

 

[bitoiu]

Only a few hours pass and I already have the same problems:

• The WebUI for the router config doesn't load
• 5GHz has disappeared
• Can't connect to my mac server

I followed the tutorials to the letter, to try and avoid spending money on a new router, but this is just now wasting time. ax88u here I go. @L&LD do you have your own "Defaults Guide" for the AX88U? I've seen your comments on MIMO and there's a huge thread that spans 2 years I think. Is there a summary of "this is the recommended/tested defaults for the 88u?

Thanks all.

 

[L&LD]

@bitoiu can you post screenshots of what you have configured? (Sorry, not able to concentrate too much on the forum here right now).

 

[bitoiu]

@bitoiu can you post screenshots of what you have configured? (Sorry, not able to concentrate too much on the forum here right now).

@L&LD to be honest I didn't setup much, after the guides. In terms of config it's pretty much standard. I've been fighting this battle to see if I could hold the router for a bit longer, but the AX88U is on the post, arrives Tuesday. @L&LD the only thing I would ask you is if you have a post somewhere you can link where you have the optimal settings for the AX88U?

> (Sorry, not able to concentrate too much on the forum here right now)

Please @L&LD, you've already helped enough

 

[L&LD]

@bitoiu I don't have a post with settings specifically for the RT-AX88U. But the M&M Config guide and the general recommendations from others on the forums here are very close to what I continue to use. I hope this helps a little.