<div dir="ltr"><div class="gmail_quote"><div dir="ltr">On Tue, Jul 11, 2017, 22:24 Ian Pilcher <<a href="mailto:arequipeno@gmail.com" target="_blank">arequipeno@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On 07/11/2017 02:58 AM, Lennart Poettering wrote:<br>
> Note that DHCPv6 is not done unless IPv6 RA packets tell networkd to<br>
> do so. Hence, areyou sure the RA spoken on your network properly<br>
> indicates that?<br>
<br>
Interesting. I am seeing somewhat different behavior (but note that<br>
this is systemd-networkd 219 on CentOS 7, which is pretty old).<br>
<br>
* On networks with no router advertisements at all, systemd-networkd 219<br>
will eventually send out dhcp6 solicit packets.<br>
<br>
* On a network with router advertisements that include prefix info<br>
(option 3), systemd-networkd 219 will send dhcp6 solicit packets.<br>
<br>
* If the router advertisements on a network do not include any prefix<br>
information, however, systemd-networkd 219 will never send any dhcp6<br>
solicit packets and never configure an IPv6 address.<br>
<br>
Unfortunately, my ISP's router sends RAs without prefix information.<br>
(Clients get their addresses via DHCPv6, and are presumably expected to<br>
simply assume a 64 bit prefix length.)<br>
<br>
So it looks like I won't be able to use systemd-networkd to get around<br>
the dhclient wall clock problem, at least until RHEL/CentOS see an<br>
updated version of systemd (systemd-networkd 231 does seem to behave<br>
differently).<br></blockquote></div><div><br></div><div>What<span style="font-size:13px"> global flags do each network's RAs have? If I remember correctly, there are two, "Managed Addresses" and "Managed Other", which trigger DHCPv6 – if neither of them is set, that is supposed to mean DHCPv6 is unneeded.</span></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
</blockquote></div></div>