AC5300 WLAN to WLAN connectivity issues

[mgrharry]

Recently setup an RT-AC5300. It was new in box, but had been sitting on a shelf for about a year. I flashed firmware to the latest Merlin version, RT-AC5300_386.7_2 and setup router. Initially everything seemed fine, but after a while I noticed that wireless devices were intermittently having issues communicating with other wireless devices. At first I thought it might be a specific PC that was having firewall issues, but then noticed that it was affecting multiple devices. Here's what would happen -- I had two printers setup on WiFi. I assigned them fixed IP addresses using the manually assign by MAC address feature. However, different computers would intermittently have issues connecting to the printers. Sometimes they would work, then for no apparent reason, they would stop being able connect and would be unable to ping any local IP addresses but they would still have internet connection. At the same time, another WiFi connected computer might be able to print and ping them successfully, or it might not. There seemed to be no obvious pattern, aside from the fact that if I started a continuous ping of the printer IP address from a WiFi device, it would typically retain connection until some point after I manually stopped pinging. However, WiFi devices were able to connect to and ping wired devices consistently and without any issues, and wired devices could also ping all WiFi devices without problem. All devices had strong WiFi signal, and the issue was not caused by any client side software firewall or setting. It was as though the router was intermittently subjecting some WiFi devices to wireless isolation, despite the fact that this was not a guest network.

I thought perhaps it was a bug of some type with the Merlin firmware, so I reflashed it back to the latest Asus firmware and did a factory reset but still experienced the same problem. I also tried a 2x older versions of Asus stock firmware and had same issue. Since it didn't seem to be firmware related, I ended up flashing back to latest Merlin version.

As a temp workaround, I hardwired the two printers that had been connecting via WiFi, but long term this issue needs to be resolved.

Any one have some idea of how to track down what is causing this issue?

 

[Frank Monroe]

I have been having this exact same issue on my RT-AC5300 for months. It started with the release of version 386.4_0. The problem goes away if you revert back to version 386.3_2. The problem is especially an issue for me because I"m on an IPv6 network and this problem eventually stops IPv6 ICMP just like IPv4 pings. When they stop, clients eventually lose their IPv6 client information as the IPv6 RA's never make their ways to the devices.

 

[mgrharry]

Ahh, glad to hear I'm not the only one. Interesting to know that 386.3_2 (Merlin fw i assume?) works for you. I did try some older versions, but don't think I went that far back. I'll try that version when I get a chance and see if it works. Anyone else out there with insight on this?

 

[Frank Monroe]

Well, when I fist noticed the issue was immediately after the January release (386.4_0). At that time going back to 386.3_2 wasn't really that far. Since then, I have tested every release as they came out. They all have had the issue. The issue or variations of the issue has been reported in this forum multiple times since January. So far, there hasn't been the slightest curiously about the issue from other community members. In my case, I have been living with the issue in hopes that it will be fixed in the next major Merlin release along with backing out of some of the DNSfilter changes introduced in 386.7_2.

 

[Frank Monroe]

This issue originally started happening once a week. It increased to 1-2 times a day. Each time it occurred I had to reboot the router to fix the issue. A couple of days after you reported the exact same issue, I downgraded back to 386.3_2 just to make sure it actually fixed the issue. As before, the problem has gone completely away. So the issue was introduced in 386.4_0. I eagerly await the release of version 388 for the AC5300 in hopes this issue will fixed in that release.

 

[asusrunshot]

This issue originally started happening once a week. It increased to 1-2 times a day. Each time it occurred I had to reboot the router to fix the issue. A couple of days after you reported the exact same issue, I downgraded back to 386.3_2 just to make sure it actually fixed the issue. As before, the problem has gone completely away. So the issue was introduced in 386.4_0. I eagerly await the release of version 388 for the AC5300 in hopes this issue will fixed in that release.

I have a similar problem with AC3100 and HP laserjet.

I had to turn on IPv6 for the printer to stay connected. Maybe try that?

 

[Frank Monroe]

I'm on an IPv6 network. This problem is worse on IPv6 networks because as the issue progresses, you end up not receiving RA's from the router and eventually external IPv6 traffic stops. I'm not trying to fix a printer like the OP, I'm trying to fix the entire problem.

 

[BlueFrog]

This issue originally started happening once a week. It increased to 1-2 times a day. Each time it occurred I had to reboot the router to fix the issue. A couple of days after you reported the exact same issue, I downgraded back to 386.3_2 just to make sure it actually fixed the issue. As before, the problem has gone completely away. So the issue was introduced in 386.4_0. I eagerly await the release of version 388 for the AC5300 in hopes this issue will fixed in that release.

Same, sitting at 386.3_2 on my AC5300 until this is resolved. I can't use any of my ChromeCast devices if I upgrade.

 

[mgrharry]

For those sitting on old firmware, there's also this to consider:

Update your Asus router's firmware right now or risk botnet infection

New firmware protects a range of Asus Wi-Fi routers from the emerging Cyclops Blink botnet.

www.pcworld.com

TLDR is Asus routers are being targeted by a botnet with older firmware affected.
Not clear if 386.3_2 is affected, but seems like it would be. Although details on how that botnet infects devices are unclear. If remote management is disabled then maybe it's not a problem?

 

[L&LD]

Advanced search results | SmallNetBuilder Forums (snbforums.com)

 

[BlueFrog]

Anyone tried "386.9 beta 1" to see if this is fixed in the latest build?

 

[Frank Monroe]

Anyone tried "386.9 beta 1" to see if this is fixed in the latest build?

I did. Its not fixed.

 

[BlueFrog]

I did. Its not fixed.

That's unfortunate. I would really like to upgrade to a later version, but I need to be able to use Chromecast and other features. Thanks for the test.

 

[Frank Monroe]

That's unfortunate. I would really like to upgrade to a later version, but I need to be able to use Chromecast and other features. Thanks for the test.

I am disappointed as well. The problem is likely with the native Asus firmware and not the Merlin modifications. Unfortunately, I haven't had the opportunity to test which version of the native Asus introduced the issue because I can't run without Merlin for long enough to test.