Re: Failed TCP connection reset when processing overlapping data segments

[Anil Madhavapeddy <avsm2@xxxxxxxxxxxx>]

> On Apr 16, 2025, at 8:28 AM, Lucas Aubard <lucas.aubard@xxxxxxxx> wrote:
> 
> The behavior you describe for processing overlapping data segments makes 
> sense to me.

I must admit I'm still in the dark as to why this makes more sense today to do 
this than in 2013, when we dropped that data in preference for an unambiguous 
retransmission in case the stack was under attack. What's changed such that we 
can now accept overlapping TCP segments for the same data?

There are a few reasons I can think of that may explain it (but I haven't 
checked):
- perhaps datacenter Linux wants to avoid retransmissions at all costs
- perhaps the security model has been revved somehow to delegate this to the 
higher levels of the stack (DTLS)
- or perhaps out of order transmissions are more common (multipath?) so we now 
need to deal with it.

I'm not really sure which of these are true or not, but without determining 
this, it seems unwise to depend on other stacks' behavior here.

best,
Anil