How to slow DNS queries?

[justinglock40]

I’m having an issue where sometimes the DNS Server will stop responding temporarily for like a minute or two.

I’m running in AX86U. I personally think it’s because it’s getting slammed with requests. Any help with this would be greatly appreciated.

 

[heysoundude]

which DNS server is that?

 

[Gary_Dexter]

I’m having an issue where sometimes the DNS Server will stop responding temporarily for like a minute or two.

I’m running in AX86U. I personally think it’s because it’s getting slammed with requests. Any help with this would be greatly appreciated.View attachment 47112View attachment 47113View attachment 47114

What's the Rate Limit you have set in AGH?

 

[justinglock40]

which DNS server is that?

Adguard Home

 

[justinglock40]

What's the Rate Limit you have set in AGH?

View attachment 47119

Default of 20

 

[Gary_Dexter]

Default of 20

You can reduce the rate limit then see if that works

 

[SomeWhereOverTheRainBow]

I’m having an issue where sometimes the DNS Server will stop responding temporarily for like a minute or two.

I’m running in AX86U. I personally think it’s because it’s getting slammed with requests. Any help with this would be greatly appreciated.View attachment 47112View attachment 47113View attachment 47114

It is actually probably caused by AdGuardHomes ratelimit option. I personally believe they set a very low per client ratelimit. which means each of your clients are being ratelimited when they hit a certain amount of queries in a given period of time. This is completely correctable by adjusting the ratelimit settings in the AdGuardHome DNS settings page. (the same page that list the upstream servers). You could try dropping it to 16 which is the default for pihole. However, if you are only servicing network clients it would be completely acceptable to raise the ratelimit number for testing purposes. While ratelimiting (or slowing dns queries per client) reduces the risk of certain types of DNS amplication attacks, it can quickly create DNS query congestion in a local network servicing only Home network clients. Another option you could try adjusting is to use your Upstream DNS servers in parallel which may improve serving query answers more promptly. I recommend using more than one Upstream DNS server as well for better dns resolution resilience.

 

[justinglock40]

Thank you. I ended up removing it because it was causing congestion. And went back to pihole. Maybe will revisit in the future