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hAP ac^2 Suddenly stopped reaching gateway periodically

Posted: Sat Aug 24, 2019 9:31 pm
by maretodoric
Hello everyone.

So I've had hAP ac2 for a week or so, and everything was working perfectly fine ! I'm very much satisfied with this device.
However, today something strange happened.
Suddenly, MikroTik was unable to ping gateway.

I have a router that is connected to my ISP via coaxial cable.
On my ISP router ( i have several devices connected to it via ethernet cable.
MikroTik is connected to that router also via ethernet cable on the other side of the wall.
In order to communicate with other devices that are physically connected to my ISP Router, I've set MikroTik in bridge mode even on ether1 port, assigned it address ( from same LAN subnet as internal ISP routers network, but I've set in MikroTik DHCP Server an option that he is the gateway.

However, here comes the weird part.
Today, out of nowhere, from time to time MikroTik decided he cannot see my ISP router that is directly connected to via ethernet cable. I noticed that because devices started loosing internet connection. When doing troubleshooting, i could see that when pinging ISP router ( from MikroTik device, packets will go through without packet loss and all of a sudden, a timeout will occur for couple of seconds, approx 10-15 packets. And then it will ping again and again drop.

I thought it might be a cable between mikrotik and ISP router, so I've connected my PC directly to it, but there was no packet loss.
From time to time i also failed to ping MikroTik device itself from other devices in my home. When that happens, i could access MT ONLY from MAC Telnet, not via IP address. So something happened to it, don't know what.

What seemed to have resolved the issue (for now), is that i have performed a factory reset of MikroTik device , and it seems to be working again.
What could cause this issue? I have backed up MikroTik config using /export prior to restoring to factory defaults , so if anyone need to see some configuration that i was using, let me know.

Thanks in advance

Re: hAP ac^2 Suddenly stopped reaching gateway periodically

Posted: Tue Aug 27, 2019 7:37 pm
by maretodoric
Happened again so here is what I've noticed.
Not only that MikroTIk will stop pinging the gateway, but devices on LAN will also stop pinging MikroTik.
For example, if i connect Laptop via WiFi to MikroTik SSID (or my ISP router wireless AP) at the same time when MikroTik stops seeing the gateway, laptop will also not see (ping) MikroTik to it's bridge IP. But, even if i am connected to MikroTik SSID, i could still see other devices on LAN.
Could this be a hardware issue related to MikroTik or some weird bridging loop? How could i troubleshoot this?

Re: hAP ac^2 Suddenly stopped reaching gateway periodically

Posted: Wed Aug 28, 2019 8:32 am
by mkx
I've had similar issue with RBD52G, which went away after I did the following two things:
  • upgrade ROS to 6.44
  • effectively stopped using switch chip for forwarding the traffice between ether ports (my setup includes VLANs and I configured bridge vlan-filtering which means all ethernet frames have to pass CPU).

Before that I had to set up watchdog (pinging local managed switch) and it would reboot device up to 20 times a day. After mentioned changes, it's running rock solid.

Re: hAP ac^2 Suddenly stopped reaching gateway periodically

Posted: Wed Aug 28, 2019 12:01 pm
by maretodoric
Thanks for your reply.

I was using ROS 6.45.3 until i upgraded to 6.46beta34. Seems MAYBE more stable this was. For example yesterday after update it continued to do the same thing, but after an hour it stabilized and it doesn't seem to be happening again. Would you advise to downgrade to 6.44?

I've enabled bridge event logging and debug event sent to my local syslog server to see if i could figure something out if it starts happening again. It seems more stable now that I've moved all default gateway settings back to my ISP router ( instead of MT ( But as i said, I've yet to investigate.

As for stopped using switch chip for forwarding, how am i suppose to do that? My Setup doesn't include any VLANs at this point.

Re: hAP ac^2 Suddenly stopped reaching gateway periodically

Posted: Wed Aug 28, 2019 10:07 pm
by mkx
Regarding ROS version: my RBD52G is currently running 6.45.1 and is stable.

Regarding disabling switch-chip: set hw=no on all ether ports in /interface bridge port. You can verify the status by executing /interface bridge port print ... before disabling HW offload those ports should have a 'H' in the flags column left from interface names and after disabling it there shouldn't be any 'H's ...

Re: hAP ac^2 Suddenly stopped reaching gateway periodically

Posted: Fri Aug 30, 2019 12:37 pm
by maretodoric
Yup, sounds about right.

I'll give this a try then test and check back with results. Thanks a lot!

Re: hAP ac^2 Suddenly stopped reaching gateway periodically

Posted: Mon Sep 09, 2019 11:44 pm
by maretodoric
OK So I've figured something new out. It would seem that everything was working fine up until today. Today i reverted back to stable release (6.45.5) and issue started happening again. But this time, it would seem to be related to my Laptop only! Not sure why.

I got my Raspberry Pi (connected via 5GHz WiFi), home server (Directly connected to technicolor router) and PC (directly connected to MT) all could ping mikrotik without any issues.
But my laptop (connected via 5GHz WiFi to MT) would have EXTENSIVE packet loss when pinging MT.
What I've figured out, and i cannot realize why and that is why i need help from you guys, laptop would ping WITHOUT packet loss IF and ONLY IF some kind of sniffer is active on MT side.
No matter if that is a Torch of wlan2 interface or Packet Sniffer from Tools/Packet Sniffer (also on wlan2 int). But if some kind of sniffer is running, all packets route without issues. This time I've removed ALL firewall rules and I've made technicolor main router again (all devices have TC as default gw) but ping issues persists. I will consider moving again to Beta firmware if this continues to see if that will help again.