I'm happy this is sensible.
Patch applied.
Simon.
On 12/01/2022 03:42, Brian Hartvigsen wrote:
> To be clear the 1232 number was not a “finger in the wind” number, as
> noted on the flag day page:
>
> An EDNS buffer size of 1232 bytes will avoid fragmentation on nearly all
> current
To be clear the 1232 number was not a “finger in the wind” number, as noted on
the flag day page:
An EDNS buffer size of 1232 bytes will avoid fragmentation on nearly all
current networks. This is based on an MTU of 1280, which is required by the
IPv6 specification, minus 48 bytes for the IPv6
Hey Petr,
at least one popular upstream DNS provider (Quad9 at 9.9.9.9 and
their other addresses) switched from 1280 to 1232. This means the
"should always work" size of dnsmasq is slightly too large for
them and might fails for those queries where the payload lies in
between these two values.
I doubt that small difference matters. 1280 or 1232 is almost the same.
It is about the smallest packet supported by IPv6. I think size 1232 was
invented by more or less sophisticated guessing. I am not sure this is
required to be exactly this value. I would leave it at the current value
unless we
Hey Simon,
Minimum safe size is recommended to be 1232. See
https://dnsflagday.net/2020/, relevant parts below:
> This year, we are focusing on problems with IP fragmentation of
DNS packets.
>
> IP fragmentation is unreliable on the Internet today, and can
cause transmission failures when large
