[arch-general] dhcpcd-7.0.1-1 seems to break SLAAC

[Jukka Salmi]

Hello Andy

ProgAndy --> arch-general (2018-02-23 23:09:07 +0100):
> Am 23.02.2018 um 01:45 schrieb Jukka Salmi:
> > With dhcpcd-6.11.5-1 starting this netctl profile results in an IPv4
> > address being configured via DHCP and an IPv6 address being configured
> > via SLAAC as expected.
> > 
> > With dhcpcd-7.0.1-1 starting this netctl profile results in an IPv4
> > address being configured via DHCP, but no IPv6 address is configured.
> > 
> > ...
> > 
> > Is anybody seeing the same issue?  Is really dhcpcd to blame?
> > 
> > 
> > TIA & cheers,
> > 
> > Jukka
> > 
> Hello,
> that was a deliberate design decision, it is assumed that you will
> either want dhcpcd to handle ipv4 as well as ipv6 or you want to
> disable ipv6.
> 
> https://roy.marples.name/archives/dhcpcd-discuss/0001903.html
> 
> >   *  ipv6: disable kernel RA if interface is active
[...]
> More information about the reasons for the change here:
> https://roy.marples.name/archives/dhcpcd-discuss/0001907.html
> https://roy.marples.name/archives/dhcpcd-discuss/0001880.html

Thanks for the hints.  So it seems that currently a netctl profile with

        IP=dhcp
        IP6=stateless

is just not working as expected, at least not when using the default
setting of DHCPClient=dhcpcd.


> It seems that there were too many complaints, so in git the behaviour
> has been changed again. (After the 7.0.1 release)
> https://roy.marples.name/archives/dhcpcd-discuss/0001942.html
> https://github.com/rsmarples/dhcpcd/commit/8f483d192082a953dd035f38ee4555735106f1fc
> > /*
> > * If dhcpcd is doing RS, disable RA support
> > * in the kernel. Otherwise, leave it alone.
> > * Logically it should be disabled regardless as dhcpcd can
> > * do it better and the user saying no RS means no RS even the kernel,
> > * but some crazy people want the kernel to do it still.
> > */
> 
> Maybe in the future dhcpcd will have options for both ignoring ipv6
> (letting the kernel handle it) and disabling ipv6.

I wouldn't complain about such options ;)


Cheers, Jukka

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