AdGuardHome AdGuard Home Intermittent DNS

[CntrlAltDel]

Hi there,
Over the last couple of months I've been using Adguard Home on OPNsense and during the entire time I noticed intermittent DNS issues where all requests will be dropped seemingly for no reason. The internet connection will still be up but just for random periods DNS queries will fail. I've now moved back to Asus Merlin with AdGuard Home installed on my RT-AC88U and I'm seeing the exact same behaviour. Is anyone facing anything similar and if so what do you do to resolve it?

 

[cptnoblivious]

I've run AdguardHome both on the routers and on separate systems (i.e. on a rasp pi and one in a VM). I've not seen what you describe, though while on the router every now and then it would seem to 'hiccup' slightly which is why I moved it off it.

If the upstream DNS is slow, I've seen some issues and I now point to 2 different upstream DNS providers (i.e. Cloudflare and canadianshield in my case).
FYI.

 

[saison2023]

Yes, this is happening (too) many times from the beginning of this year. Sometime before this summer, I had to do a router factory reset because AGH "locking" the router and even after a reboot, uninstallation and other troubleshooting steps, the router was not behaving correctly.
I am trying to see if a monthly reboot could help.
When trouble appear, in general the first sign is when I can see in the router's system logs is that AGH is unable to communicate with all the DNS servers configured. I am using family safety settings ("browsing security web service" and "parental control web service"), and the first problem is with AdGuard Familly DNS servers (https protocol).
To avoid wasted ressource consumption, I tried to lower the memory settings in DNS cache configuration (from 4096, 2048 and now 512mb) and to reduce logs and statistics retention period (from 90 days to 30 days).
Last year, I was able to use 4096mb and 90 days in retention without any issue. I didn't change my router from a long time, it is the same model when everything was working fine.

 

[Paul1942]

I was have issues with AGH where all requests will be dropped seemingly for no reason only on wifi.
These changes fixed the issue for me:
DNS server configuration
Set Rate limit=0

DNS cache configuration
Enable Optimistic Caching

 

[balr0g]

I was have issues with AGH where all requests will be dropped seemingly for no reason only on wifi.
These changes fixed the issue for me:
DNS server configuration
Set Rate limit=0

DNS cache configuration
Enable Optimistic Caching

To OP, also did below for stable AGH:
* enabled swap (I'm assuming you did, adding here for completeness.)
* enabled chrony/ntp in merlin amtm.
* judicious use of mini dns blockers (hagezi.oisd,etc.) as i think you have 512MB of RAM.

 

[saison2023]

To OP, also did below for stable AGH:
* enabled swap (I'm assuming you did, adding here for completeness.)
* enabled chrony/ntp in merlin amtm.
* judicious use of mini dns blockers (hagezi.oisd,etc.) as i think you have 512MB of RAM.

Thanks for sharing and for trying to help. Everyone ideas are more than welcome!

• Swap: I created a 10 GB swap file
• NTP is enabled in AMTM, not sure about chrony (doesn't understand/know what this is)
• My router is RT-AX86U with 1024 MB of RAM. I can test to lower filters list, but as I said, it was working with the same router and AGH config until recently.

I already tried to factory reset and configured everything from scratch but the trouble comes back after a certain period of time.

 

[privacyguy123]

* enabled swap (I'm assuming you did, adding here for completeness.)
* enabled chrony/ntp in merlin amtm.

I have literally never heard of these options and can't find them?

 

[saison2023]

I have literally never heard of these options and can't find them?

Could be a good starting point : amtm step-by-step install guide - L&LD
As least for swap.