[arch-projects] [netctl] Regarding commit fe5f0d6fe - "Restrict dhcpcd to IPv4"

Jouke Witteveen j.witteveen at gmail.com
Sun Jun 16 04:35:12 EDT 2013

On Fri, Jun 14, 2013 at 6:45 PM, Thomas Bächler <thomas at archlinux.org> wrote:
> The behaviour introduced by commit fe5f0d6fe is undesirable. To quote
> the manpage:
> "dhcpcd is also an implementation of an IPv6 Router Solicitor as
> specified in RFC 4861 and RFC 6106.  dhcpcd can optionally handle
> address and route management itself, and will do so by default if Router
> Solicitation is disabled in the kernel.  If dhcpcd is managing routes,
> dhcpcd sends Neighbor Solicitions to each advertising router
> periodically and will expire the ones that do not respond."
> What this doesn't mention is that it also reads DNS servers from Router
> Advertisements, which the kernel cannot do by itself. dhcpcd does not
> perform dhcpv6 as far as I know.

I'm not sure; it might do so nowadays. Does dhclient read DNS servers
from RAs in IPv4 mode?

> IMO, we should remove the -4 flag from dhcpcd if IP6=stateless is set.

The flag was added because in most situations leaving it out causes a
timeout in acquiring an IPv6 lease.

My initial thoughts:
: If dhclient doesn't extract the addresses from RAs in IPv6 mode, we
shouldn't expect dhcpcd to do so
: If dhclient does, this might be a bug in dhcpcd

- Jouke

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