Re: [PATCH] Don't allow Managed DHCPv6 to short-circuit SLAAC

[Tore Anderson <tore fud no>]

Another thing I noticed just now, is that when you set the mode to
DHCPv6 only, RA processing are disabled (accept_ra=0). This also seems
wrong, as RAs are the *only* way an IPv6 node can automatically discover
the default gateway address. DHCPv6 can not carry this information.

In the DHCP-only mode, NM appears to instead add a on-link route to the
entire ::/0 into the kernel, which certainly is the wrong thing to do.

While possible, performing DHCPv6 without at the same time processing
RAs in order to discover the router address seems quite pointless. You
could of course change the DHCP-only mode so that it did look for RAs
but did not perform SLAAC (set sysctl accept_ra_pinfo=0). However, I
feel that this is likely to be a quite out of the ordinary
configuration, and that it is better to simply remove the DHCP-only mode
completely and instead tell users wich such specialiced requirements to
simply set the necessary sysctls themselves.

What do you think?

Best regards,
-- 
Tore Anderson