Bug#987815: MPTCP is not enabled

[Salvatore Bonaccorso <carnil@debian.org>]

Control: tags -1 + confirmed

Hi,

On Fri, Apr 30, 2021 at 11:18:40AM +0200, chrysn wrote:
> Source: linux
> Version: 5.10.28-1
> Severity: wishlist
> 
> 
> The current configuration does not enable the multipath TCP
> functionality provided by the kernel through the MPTCP (and the
> the-default MPTCP_IPV6) binary options.
> 
> These have been available since kernel version 5.6.
> 
> When enabled, user space applications can opt in to MPTCP behavior by
> using the new IPPROTO_MPTCP; regular TCP connections are unaffected.
> 
> Applications using this are starting slowly (outside of the Apple
> ecosystem where this has been in used for years to ensure smooth network
> handovers), but having this available widely would make it easier for
> application developers to verify MPTCP operation on systems where they
> can't easily (or don't have the experience to) rebuild their kernel with
> CONFIG_MPTCP=y.
> 
> Please consider enabling this feature.

I do agree, and there were requests as well offlist/offbts on this,
though we won't enable it anymore at this stage of the bullseye
release preparations for bullseye but will follow in a later
experimental upload.

Regards,
Salvatore