[Dnsmasq-discuss] Using IPv6 DHCP

Tue Sep 25 13:53:25 BST 2012

Addendum:
A test Windows 8 box registered fine with its hostname (DNS forward
and reverse looks are fine too).

Ubuntu 12.04 has issues, e..g
https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/991360
I've not found a solution yet though.

Sean

On 25 September 2012 14:38, Sean Boran <sean at boran.com> wrote:
> Hi,
>
> Ah. Its works, magic. 'Doh', as they say over the water).
> So, I should use the option ra-names?
>
> I now see logs like:
> Sep 25 13:57:39 sisdns6 dnsmasq-dhcp[2282]: 14525054 DHCPSOLICIT(eth0)
> 00:01:00:01:00:50:10:5a:de:08
> Sep 25 13:57:39 sisdns6 dnsmasq-dhcp[2282]: 14525054
> DHCPADVERTISE(eth0) 2001:918:ffcb:199::16 00:01:00:01:00:50
>  :10:5a:de:08
> And the test client has correctly received 2001:918:ffcb:199::16.
>
>
> However, if I may piggyback a question, how do I get this into DNS?
>
> host 2001:918:ffcb:199::16 localhost
> Using domain server:
> Name: localhost
> Address: 127.0.0.1#53
> Aliases:
> Host 6.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.9.1.0.b.c.f.f.8.1.9.0.1.0.0.2.ip6.arpa
> not found: 3(NXDOMAIN)
>
> Hmm. Looking at /var/lib/misc/dnsmasq.leases there is a star for the hostname.
> So maybe the problem is ubuntu not sending a hostname.
> Is there any additional option to allow dnsmasq to be more inventive
> in finding out the hostname to map?
> Of make dnsmask log what details it has received in the request?
>
>
> Thanks,
>
> Sean
>
>
>
>
>
>
> On 25 September 2012 13:45, Simon Kelley <simon at thekelleys.org.uk> wrote:
>>  Doh!
>>
>> I didn't read your config carefully enough. You're declaring the dhcp-range
>> as "ra-stateless", which tells dnsmasq to advertise that subnet via
>> router-advertisements, and set the bits which tell the clients to use DHCPv6
>> for configuration, but not address allocation.
>>
>> Clients are expected to send DHCP information-requests for DNS servers, NTP
>> servers, etc, etc, but won't get IP addresses allocated via DHCPv6. Hence
>> dnsmasq is refusing to allocate and address.
>>
>> Remove ra-stateless from your config and it will all work.
>>
>>
>> (On the v6-only question, if you don't supply a DHCPv4 address range, then
>> dnsmasq won't reply to DHCPv4 requests.
>>
>> Cheers,
>>
>> Simon.
>>
>>
>> On 25/09/12 10:41, Sean Boran wrote:
>>>
>>> Hi,
>>>
>>> On 25 September 2012 10:27, Simon Kelley <simon at thekelleys.org.uk> wrote:
>>>>
>>>> On 25/09/12 09:10, Sean Boran wrote:
>>>>>
>>>>>
>>>>> Hi,
>>>>>
>>>>> I'm doing sdome DHCPv6 tests and have a few questions :-)
>>>>>
>>>>> First is it is possible to disable v4 respond, and only respond to v6
>>>>> requests? When testing I dont want to disturb a v4 dhcp already
>>>>> running.  (e.g. should I set listen-address to my IPv6 address?)
>>>>
>>>>
>>>>
>>>> If you're happy to use the very latest code, then grab 2.64test5 and add
>>>> dhcp-ignore=!DHCPv6
>>>>
>>>> to your configuration.
>>>
>>>
>>> I also disable "enable-ra", since ra should not be needed, when using
>>> dhcp?
>>>
>>>
>>> Sep 25 11:33:55 sisdns6 dnsmasq[9577]: started, version 2.64test5
>>> cachesize 150
>>> Sep 25 11:33:55 sisdns6 dnsmasq[9577]: compile time options: IPv6
>>> GNU-getopt no-DBus no-i18n no-IDN DHCP DHCPv6 no-Lua TFTP no-conntrack
>>> Sep 25 11:33:55 sisdns6 dnsmasq-dhcp[9577]: DHCPv6 stateless on
>>> 2001:918:ffcb:199::10
>>> Sep 25 11:33:55 sisdns6 dnsmasq-dhcp[9577]: SLAAC on
>>> 2001:918:ffcb:199:: prefix valid 1d
>>>
>>>
>>>>>
>>>>> Secondly, I'm having issues assigning v6 addresses.
>>>>>
>>>>> compiled dnsmasq-2.63, config:
>>>>> --
>>>>> domain=mydomain.net
>>>>> dhcp-range=2001:918:ffcb:199::10, 2001:918:ffcb:199::20, ra-stateless,
>>>>> 24h
>>
>>                                                              ^^^^^^^^^^^
>>
>>>>> dhcp-sequential-ip
>>>>> enable-ra
>>>>> dhcp-option=option6:dns-server,[::]
>>>>> log-dhcp
>>>>> --
>>>>>
>>>>
>>>> Does the relevant interface have an address on the 2001:918:ffcb:199::
>>>> subnet, and prefix length 64?
>>>
>>>
>>> Yes.
>>>
>>>   ifconfig
>>> eth0      Link encap:Ethernet  HWaddr 00:50:56:83:3a:d4
>>>            inet addr:10.90.199.11  Bcast:10.90.199.255  Mask:255.255.255.0
>>>            inet6 addr: 2001:918:ffcb:199:fc54:9480:e886:e639/64
>>> Scope:Global
>>>            inet6 addr: 2001:918:ffcb:199:250:56ff:fe83:3ad4/64
>>> Scope:Global
>>>            inet6 addr: fe80::250:56ff:fe83:3ad4/64 Scope:Link
>>>
>>>
>>>>
>>>> Please could you try without the dhcp-sequential-ip option. That's
>>>> unlikely
>>>> to have been well tested for DHCPv6, and smells suspicious to me.
>>>>
>>>> Cheers,
>>>>
>>>> Simon.
>>>
>>>
>>> Thanks done that, but no change really.
>>>
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 available DHCP
>>> range: 2001:918:ffcb:199::10 -- 2001:918:ffcb:199::20
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 DHCPSOLICIT(eth0)
>>> 00:01:00:01:00:50:10:5a:de:08
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 requested options:
>>> 24:domain-search, 39:FQDN, 23:dns-server,
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 requested options:
>>> 31:sntp-server
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 tags: DHCPv6, eth0
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 sent size: 10
>>> option:  1 client-id  00:01:00:01:00:50:10:5a:de:08
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 sent size: 14
>>> option:  2 server-id  00:01:00:01:17:f2:f6:90:00:50:56:83:3a:d4
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 sent size: 40
>>> option:  3 ia-na  IAID=1451433281 T1=0 T2=0
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 nest size: 24
>>> option: 13 status  2 No addresses available
>>> Sep 25 11:38:46 sisdns6 dnsmasq-dhcp[937]: 7022133 sent size: 16
>>> option: 23 dns-server  2001:918:ffcb:199:fc54:9480:e886:e639
>>>
>>> Regards,
>>>
>>> Sean
>>>
>>