Re: IPv6 status on Debian for workstations / DHCP networks?
On 05/07/13 15:09, Michael Richardson wrote:
> Daniel Pocock <daniel@pocock.com.au> wrote:
> > After getting servers onto IPv6, I recently had a go at trying to run
> > IPv6 on a LAN with workstations
>
> > Currently, for IPv4 a) dhcpd does not run on the router, it runs on a
> > Debian server b) the LAN uses DHCP and dynamic DNS updates between
> > isc-dhcp and bind
>
> > For IPv6, radvd is on the router: it is not clear whether dhcpd has to
> > run on the router as well or can they be different hosts (e.g. radvd on
> > the router and dhcpd on the Debian server)?
>
> dhcpd does not have to run on the router. DHCPv6 servers are found by
> multicast. Unless you set M=1 in your RAs, your hosts will not use DHCPv6
> for address allocation, so it makes little sense to attempt to tie DNS
> updates to DHCPv6 in my opinion.
I've configured radvd on the router for M=1 - so all hosts should be
using DHCPv6 and therefore DDNS should be maintained
> > Is it strongly recommended to use any of the other dhcpd servers
> > instead of ISC?
>
> not from me.
Ok, I've tried dhcpy6d as well, it seems to offer MAC address matching
(which some people may find convenient) and I've created an ITP for it
However, I haven't seen the DDNS working properly from either the ISC
dhcpd or dhcpy6d yet
> > Another issue is client configuration: it appears that NetworkManager
> > clients are able to work using stateless or stateful config
>
> > On the other hand, for somebody who does not want NetworkManager, what
> > is the recommended way to configure /etc/network/interfaces? I notice
> > that there are different ways to configure it, e.g.
>
> If it's just a client, you can just leave it out, and the kernel will do
> autoconfiguration. If you want a specific address on the client, put it in,
> but leave the gateway blank, and the default will come from RA.
>
> If you want DNS servers from the RA, then you need a seperate daemon.
Ok, thanks for that feedback
So the default Debian installation (with nothing in interfaces) would
only use SLAAC and not try stateful DHCPv6 at all - so a site admin who
wants to allow "anything" to just plug in and work should not set M=1 in
the RA?
> > When I run ifdown, I notice that the IPv4 address is released and the
> > link is brought down before the dhclient -6 process finishes releasing
> > it's IP, the process then gets stuck for a while and logs various
> > errors
>
> I haven't run dhclient6 much, so I can't comment.
>
> > Should NetworkManager and the interfaces file always bring up both IPv4
> > or IPv6 whenever possible or is it just one or the other?
>
> both.
One issue I've observed on older machines that have been upgraded is
that the IPv6 setting in NetworkManager is sometimes set to "Ignored"
while on fresh installs it is in "Automatic" mode - so people who have
upgraded need to go in and change that or they won't experience dual stack.
Reply to: