Adguard DNS buffer size too small

[askhe8]

Hey there, recently setup a new AX-68U with Merlin 386.72. I have setup Adguard and Skynet with mostly default settings and everything is functioning very well. I checked my syslog and have been seeing occasional errors from adguard:

Aug  3 09:52:36 AdGuardHome[20795]: 2022/08/03 09:52:36.506790 [error] unpacking udp packet: dns: buffer size too small
Aug  3 09:52:39 AdGuardHome[20795]: 2022/08/03 09:52:39.547838 [error] unpacking udp packet: dns: buffer size too small

/proc/sys/net/core/rmem_max is already set to 2500000 by default as someone in another thread suggested. I'm wondering what else I can do to address this issue. Github and other forum posts/threads here have not revealed anything else I can do. I've used Merlin on all previous ASUS routers, but this is my first time setting up Adguard/Skynet. I've been lurking on the forum for a long time, but this is my first time posting. Any help is greatly appreciated. Thanks!

 

[rankok]

Sorry to bump an old thread, but any solution for this error?

 

[SomeWhereOverTheRainBow]

Hey there, recently setup a new AX-68U with Merlin 386.72. I have setup Adguard and Skynet with mostly default settings and everything is functioning very well. I checked my syslog and have been seeing occasional errors from adguard:

Aug  3 09:52:36 AdGuardHome[20795]: 2022/08/03 09:52:36.506790 [error] unpacking udp packet: dns: buffer size too small
Aug  3 09:52:39 AdGuardHome[20795]: 2022/08/03 09:52:39.547838 [error] unpacking udp packet: dns: buffer size too small

/proc/sys/net/core/rmem_max is already set to 2500000 by default as someone in another thread suggested. I'm wondering what else I can do to address this issue. Github and other forum posts/threads here have not revealed anything else I can do. I've used Merlin on all previous ASUS routers, but this is my first time setting up Adguard/Skynet. I've been lurking on the forum for a long time, but this is my first time posting. Any help is greatly appreciated. Thanks!

what servers are you using?

 

[rankok]

what servers are you using?

I using this one:

[/168.192.in-addr.arpa/]192.168.2.1
[/router.asus.com/][::]:553
[/www.asusrouter.com/][::]:553
[/lan/][::]:553
[//][::]:553

https://unfiltered.adguard-dns.com/dns-query

tls://unfiltered.adguard-dns.com
quic://unfiltered.adguard-dns.com

https://security.cloudflare-dns.com/dns-query

tls://security.cloudflare-dns.com

 

[Tech9]

https://unfiltered.adguard-dns.com/dns-query
tls://unfiltered.adguard-dns.com
quic://unfiltered.adguard-dns.com
https://security.cloudflare-dns.com/dns-query
tls://security.cloudflare-dns.com

Why?

 

[SomeWhereOverTheRainBow]

I using this one:

[/168.192.in-addr.arpa/]192.168.2.1
[/router.asus.com/][::]:553
[/www.asusrouter.com/][::]:553
[/lan/][::]:553
[//][::]:553

https://unfiltered.adguard-dns.com/dns-query

tls://unfiltered.adguard-dns.com
quic://unfiltered.adguard-dns.com

https://security.cloudflare-dns.com/dns-query

tls://security.cloudflare-dns.com

Atleast one of the DNS server on your list maybe the culprit for the UDP errors; however, this has been a known error on adguardhome in general. It is not exclusive to being an error that only appears while using AGH on Asuswrt-Merlin. It most likely has nothing to do with adguardhome and more to do with the encrypted upstream dns servers being used. If your DNS resolution is not failing, I would just assume at somepoint it will be fixed over time. If your DNS is actually failing, then I recommend using different upstreams, or using your DNS servers in parallel load balance policy to create redundancy.

But don't just take my word for it, @Tech9 has extensive experience with UDP packet errors.

 

[Tech9]

A mix of filtered and unfiltered upstream DNS servers with all DoT, DoH and QUIC is something I'm failing to figure out.

 

[SomeWhereOverTheRainBow]

A mix of filtered and unfiltered upstream DNS servers with all DoT, DoH and QUIC is something I'm failing to figure out.

I get what you mean. If I use squad9, I also use cloudflair-security, but not squad9 and plain (cloudlfair, or goggles) dns. Since squad9 has a security filtering, we would want to use another server that has a form of service filtering which is comparable.

 

[privacyguy123]

I'm seeing this error too with that cache size set to 4194304 ... I have not touched anything manually. :S

 

[robinjoo1]

hey sorry to bump this but how can i resolve this


message

May 5 18:03:17 AdGuardHome[5097]: 2024/05/05 18:03:17.835546 [error] dnsproxy: unpacking udp packet: dns: buffer size too small


settings

 

[SomeWhereOverTheRainBow]

hey sorry to bump this but how can i resolve this


message

May 5 18:03:17 AdGuardHome[5097]: 2024/05/05 18:03:17.835546 [error] dnsproxy: unpacking udp packet: dns: buffer size too small


settings
View attachment 58497

View attachment 58498
View attachment 58499


View attachment 58500


View attachment 58501

is your dns broken when you see that error? The reason I ask is because AdGuardHome produces a few messages that print at the "error" level which should actually be for "debug". If your DNS resolution is not broken, I wouldn't worry about it. If your log is flooded with that message, and you are not able to load anything or perform DNS lookups, then I would recommend worrying. I would also tell you your cache size may be way too large. You don't need one nearly that big for AdGuardHome to perform its job. I also would recommend not disabling resolving of ipv6 addresses/ or requests. I have played with that with, and without being ticked. I found a lot more of my requests were successfully resolved if I did not have that option ticked. AAAA requests typically can be resolved over ipv4 as well, so enabling this option may actually be partially crippling your dns resolution capabilities.

 

[robinjoo1]

is your dns broken when you see that error? The reason I ask is because AdGuardHome produces a few messages that print at the "error" level which should actually be for "debug". If your DNS resolution is not broken, I wouldn't worry about it. If your log is flooded with that message, and you are not able to load anything or perform DNS lookups, then I would recommend worrying. I would also tell you your cache size may be way too large. You don't need one nearly that big for AdGuardHome to perform its job. I also would recommend not disabling resolving of ipv6 addresses/ or requests. I have played with that with, and without being ticked. I found a lot more of my requests were successfully resolved if I did not have that option ticked. AAAA requests typically can be resolved over ipv4 as well, so enabling this option may actually be partially crippling your dns resolution capabilities.

No my dns is working fine

Ah ok i will change that option
I have a 120gb ssd connected via usb 3.0 so i dont think my cache size is to big

 

[SomeWhereOverTheRainBow]

No my dns is working fine

Ah ok i will change that option
I have a 120gb ssd connected via usb 3.0 so i dont think my cache size is to big

Cache isn't talking about your ssd, it is talking about the available ram storage on the device.

 

[robinjoo1]

Cache isn't talking about your ssd, it is talking about the available ram storage on the device.

Ah i thought cache was going to a file on ssd here is my stats

Cpu temp seems a bit high to me tho

 

[Viktor Jaep]

Cpu temp seems a bit high to me tho

The 70's are perfectly normal...

 

[Tech9]

The 70's are perfectly normal...

You mean the interface shown or something else?

 

[Viktor Jaep]

You mean the interface shown or something else?

For a machine, 70C is normal... For a human, 70F is normal... and if you didn't overdose too much in the 70's... then everything is PERFECTLY normal!

 

[Tech9]

and if you didn't overdose too much in the 70's

I was served milk in 70's. I know some things about this period from Wikipedia.

 

[robinjoo1]

I was served milk in 70's. I know some things about this period from Wikipedia.

 

[bbunge]

I was served milk in 70's. I know some things about this period from Wikipedia.

What? You missed leisure suits and sideburns? Shame...