# "Maximum number of concurrent DNS queries reached" und "reducing DNS packet size" Meldungen

**URL:** <https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910>\
**Category:** Deutschsprachige Hilfe\
**Created:** [December 27, 2021, 8:00am UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910 "2021-12-27T08:00:26Z")\
**Posts on this page:** 9\
**Page:** 2

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**Author:** ![THG](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/thg/32/18029_2.png) [@THG](https://discourse.pi-hole.net/u/THG)\
**Post date:** [January 5, 2022, 6:01pm UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910/25 "2022-01-05T18:01:06Z")

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> [@yubiuser](#):
>
> edns-buffer-size: 1232

Jetzt wird es ja ganz verwirrend. Wozu gibt es denn dann den Eintrag edns-buffer-size: 1232 in der unbound Konfigdatei?

Habe ich einen Gedankenfehler?

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**Author:** ![yubiuser](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/yubiuser/32/12100_2.png) [@yubiuser](https://discourse.pi-hole.net/u/yubiuser)\
**Post date:** [January 5, 2022, 7:09pm UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910/26 "2022-01-05T19:09:45Z")

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> [@THG](#):
>
> Jetzt wird es ja ganz verwirrend. Wozu gibt es denn dann den Eintrag edns-buffer-size: 1232 in der unbound Konfigdatei?

Wenn z.B. ein Client unbound direkt anfragt und dieser dann die Anfrage ohne den Pi-hole weiterleitet.

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**Author:** ![deHakkelaar](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/dehakkelaar/32/674_2.png) [@deHakkelaar](https://discourse.pi-hole.net/u/deHakkelaar)\
**Post date:** [January 5, 2022, 8:30pm UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910/27 "2022-01-05T20:30:52Z")

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Question, the bit I dont understand, why does `pihole-FTL` needs to be configured with `edns-packet-max=1232` while MTU size for the `lo` interface is ridiculously high `65536`:

```auto
pi@ph5b:~ $ ip link show lo
1: lo: ... mtu 65536

```

Compared to `1500` for the `eth0` interface used by `unbound` to query upstream:

```auto
pi@ph5b:~ $ ip link show eth0
2: eth0: ... mtu 1500

```

I would have expected `unbound` instead of `pihole-FTL` to be needing configuring to use `1232` bytes for upstream?

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**Author:** ![THG](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/thg/32/18029_2.png) [@THG](https://discourse.pi-hole.net/u/THG)\
**Post date:** [January 5, 2022, 8:39pm UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910/28 "2022-01-05T20:39:37Z")

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@yubiuser

Bedeutet das dann, dass pihole bei unbound intern größere Pakete, wie z.B. 4096 nutzt?

Die Root/TLD Server aber nur max. 1232 unterstützen und es dann zu dieser Meldung kommt mit der Anpassung an 1280?

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**Author:** ![DL6ER](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/dl6er/32/281_2.png) [@DL6ER](https://discourse.pi-hole.net/u/DL6ER)\
**Post date:** [January 6, 2022, 6:14am UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910/29 "2022-01-06T06:14:27Z")

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@deHakkelaar Things have started to get mixed here. In the setup

```plaintext
Clients ---(1232 bytes for eth0)---> Pi-hole
Pi-hole ---(4096 bytes for lo)---> unbound
unbound ---(1232 bytes for eth0)---> the Internet

```

you could use values as suggested above. However, neither Pi-hole nor unbound (actually, no DNS server I'm aware of at all) have any settings that allow different values for in- and outbound packets. This also doesn't make much sense. If _one_ of the client retries over TCP, the entire chain has to be TCP upstream, too, according to the RFC. The [`unbound` guide](https://docs.pi-hole.net/guides/dns/unbound/) says: Both FTL and `unbound` should use the same setting when using `unbound`.

@THG Ja. Die saubere Lösung ist überall `1232` zu nutzen. Dann werden zu große Pakete sofort über TCP probiert und es kommt zu keinem ominösen Verlust bei gerade-etwas-zu-großen Paketen über UDP (die dann nach einem Timeout eh wiederholt werden würden). Die Dokumentation wurde entsprechend angepasst (siehe Link oben).

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**Author:** ![THG](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/thg/32/18029_2.png) [@THG](https://discourse.pi-hole.net/u/THG)\
**Post date:** [January 6, 2022, 8:04am UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910/30 "2022-01-06T08:04:48Z")

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@DL6ER

Ok verstehe. Das bedeutet dann aber auch, das bei unbound immer auch der nachfolgende Eintrag für pihole benötigt wird, allerdings mit 1232 und nicht mit 1280? Ist das so jetzt final richtig?

> [@yubiuser](#):
>
> Du erstellst eine Datei, z.B. `/etc/dnsmasq.d/99-edns.conf` und schreibst folgendes rein:
> 
> ```auto
> edns-packet-max=1280
> 
> ```

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<div class="post-metadata">

**Author:** ![DL6ER](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/dl6er/32/281_2.png) [@DL6ER](https://discourse.pi-hole.net/u/DL6ER)\
**Post date:** [January 6, 2022, 5:09pm UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910/31 "2022-01-06T17:09:34Z")

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Ja. Der Wert 1280 ist genau so gut, die aktuelle Empfehlung liegt aber bei 1232. Da streiten sich wirklich die Experten um den optimalen Wert. Ich denke es gibt keinen. Alles kleiner-gleich 1280 ist völlig okay.

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**Author:** ![deHakkelaar](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/dehakkelaar/32/674_2.png) [@deHakkelaar](https://discourse.pi-hole.net/u/deHakkelaar)\
**Post date:** [January 6, 2022, 5:14pm UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910/32 "2022-01-06T17:14:21Z")

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> [@DL6ER](#):
>
> @deHakkelaar Things have started to get mixed here.

Thx!  
I suspected something like this but wasnt sure.

EDIT: Ow FYI, Signiant software can use different MTU for file transfer acceleration through UDP packets for different destinations by forking a new process I believe 😉

> **[Signiant | Fast, secure file transfer software](https://www.signiant.com/)**
>
> Signiant’s intelligent file transfer software helps top content creators and distributors ensure fast, secure file transfer and delivery over all networks.

\*I couldnt find a wiki, hope the link is ok?

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<div class="post-metadata">

**Author:** ![system](https://discourse.pi-hole.net/uploads/default/original/3X/7/c/7c8792f649eeb921c5d2b4c41564ffa873d9a2b8.png) [@system](https://discourse.pi-hole.net/u/system)\
**Post date:** [January 27, 2022, 5:14pm UTC](https://discourse.pi-hole.net/t/maximum-number-of-concurrent-dns-queries-reached-und-reducing-dns-packet-size-meldungen/51910/33 "2022-01-27T17:14:38Z")

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