MTUs go strange ways - ?

Mark Lawrence nomad at
Sun Apr 3 20:14:59 UTC 2022

On Sat Apr 02, 2022 at 06:41:12PM +0100, lejeczek wrote:

>1370 (server) VS 1320 (client)
>Could some expert or two shed more light on what & why is happening?

There is a (very small) clue in the name: Maximum *Transmission* Unit.

Routing between two IP addresses is not (necessarily) symetric: routes 
are computed independently in each direction. So there is probably a 
(1320 MTU) device somewhere inbetween which is only crossed by packets 
in the client->server direction, but not in the reverse.

Mark Lawrence

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