Some IPv6 lan traffic stops routing after about 30 days

[Morac]

I have a RT-AC88U running Merlin 386.7_2. For at least a year I’ve had a problem where after about 30 to 40 days (sometimes less), some, but not all LAN traffic stops routing. I think it’s mostly ipv6, but I’m not positive about that.

Normally this presents itself by my Ecobee SmartThermostat showing up in the iOS Home app with an exclamation mark. The Ecobee uses HomePods on the network to process Siri requests and Apple uses IPv6, so when that stops working the Ecobee complains. I can also sometimes tell by trying to control my HomePods in the Home app as it will say I need to be on my Home network to do things like set timers. The HomePods can still play music and be controlled though, so not all traffic is blocked.

I can confirm there’s a problem by running an network scan app which scans my network for devices and services. Normally it returns 82 devices (there’s duplicates because it goes by IP address and most devices have both ipv6 and ipv4). When the problem occurs the devices drops to around 44 to 50. There are ipv6 addresses in the list, but not all of them. It’s possible some ipv4 addresses may be missing, but I wouldn’t really be able to tell as all lan to lan devices use ipv6.

Rarely all network traffic stops, but that happens maybe once or twice a year and I have a device that will hard reboot the router in that case.

I don’t have any plugins or third party programs running, just the bare bones Merlin firmware.

Rebooting the router resolves this problem, but I’d like to know why it’s happening and if there’s a was to fix it or work around it.

Any ideas?

 

[Frank Monroe]

This sounds like a similar problem that I am having and has been reported on this forum in various ways since version 386_4. However, 386_4 was released in January. So, it's not a quite year old. When I have the problem IPv4 traffic is fine. But, after several days, IPv6 clients lose their IPv6 DNS, IPv6 router assignment and IPv6 addresses. If you reboot the router, the problem goes away for a few days or sometimes for more than a week. In addition, I find it interesting that you have HomePods and/or Apple TV's on your network because I have also discovered that if I completely remove my Apple TV's from the network, the problem goes away entirely. The problem also goes away if I revert Merlin back to version 386_3.2. I think the reason why Apple TV's/ HomePods are involved is because somewhere around tvOS 14 or 15, Apple added Thread Networking to the product. With the addition, Apple TV's are sending out RA that I guess are causing a conflict with RA's coming from Merlin. Apparently, this was also added to iOS 16. Now that iOS 16 is on several of the devices on my network, the frequency of the problem has gone from occurring 3-4 a month to at least once a day.

 

[Morac]

I don’t think my devices completely lose IPV6 addresses as the router Ipv6 page shows they have them, but for some reason traffic stops routing.

I’m not sure if it‘s been a year exactly. I may be conflating the other problem where all LAN/WAN traffic just stops. That used to happen every 40 days to every few months for years but I haven’t seen that for awhile now so it may have been replaced with this issue.

I’ve had Apple TV and Honepods for awhile, but I just got an Ecobee in April and that’s usually how I first notice the problem.

Thread networking only works on the 2nd gen Apple TV 4K as older models lack the hardware. It also works on the HomePod minis, but not the big HomePod for the same reason. You may be mixing up Thread and Matter. The latter was added in iOS 16, but my problems predate that.

 

[Frank Monroe]

I possibly am mixing issues. However, my problems, which at least sound similar, also predate iOS 16. Mine started with the Merlin update last January.

 

[Tech9]

Mine started with the Merlin update last January.

Have you tried stock Asuswrt? At least we'll know if it's the base or something else on top.

 

[Frank Monroe]

Have you tried stock Asuswrt? At least we'll know if it's the base or something else on top.

Not yet

 

[Frank Monroe]

This just happened again just moments ago. I have been running a traffic capture for a little over 24 hours. Router announcements from my 5300 stopped about an hour ago. Also, @Morac, my devices don't immediately lose their IPv6 addresses and they do show up in the router as having them. But, eventually they do lose them due to RA's stopping. If I wait long enough, everything using IPv6 will stop. All my HomeKit devices will disappear as well.

 

[Morac]

Yesterday my router locked up and the device I had hooked up to power cycle it detected the outage, but never power cycled the router so I needed to do it by hand.

Today, less than 36 hours later the router stopped routing some Apple specific (Bonjour?) traffic so none of my Apple devices could see each other and there were only 46 hosts returned in the host scan instead of the normal 80.

I tested and IPV6 was working, but my Apple devices couldn’t see each other. I had to reboot the router again.

The only thing different the past couple of days is I powered on my Sharkbot vacuum robot which uses Wi-Fi a couple of days ago. Then I had 2 days in a row with problem. The Sharkbot also has issues frequently with acquiring an IPv6 after I reboot my router such that I have to power off the Sharkbot, then reboot the router and then power the Sharkbot back on. As such I’m wondering if it’s doing something weird to the router which stops it from routing some LAN traffic?

 

[Frank Monroe]

For me the problem goes away if I downgrade to Merlin. 386_3.2. The problem has gotten considerably worse to where it happens daily since updating my three Apple TV's to tvOS 16. Since the tvOS upgrade, my newest Apple TV which is a 4k 2nd gen model, keeps both WiFi and ethernet active at all times. WIth previous versions of tvOS, WiFI would turn off once ethernet is plugged in. Also, I am seeing IPv6 RA's coming from both the WiFi and ethernet interfaces of the 4k 2nd gen Apple TV. The RA's are supposed to be normal for HomeKit devices. But, this particular Apple TV is not the HomeKit hub. In fact, If I completely disable HomeKit on all my Apple TV's, this particular Apple TV continues to broadcast the RA's. When the problem occurs and devices lose IPv6 connectivity they either no longer have IPv6 router settings or the setting has been replace by the link local address from the RA's coming from the Apple TV. I can also see from Wireshark that the ASUS router stopped sending out RA's. I haven't figured out yet what triggers any of this.