[Dnsmasq-discuss] IPv6 dhcp strangeness

[Simon Kelley]

On 30/04/16 11:32, Kevin Darbyshire-Bryant wrote:
> Further clues maybe:  So initially when kermit comes up it grabs an IPv4
> address and I see this entry in dnsmasq's lease database:
> 1462055024 e0:3f:49:a1:d4:aa 192.168.219.4 Kermit 01:e0:3f:49:a1:d4:aa
> 
> Which looks pretty normal to me.  Then a little while later, presumably
> after a dhcpv6 request it gets changed to
> 1462055060 e0:3f:49:a1:d4:aa 192.168.219.4 Kermit
> 01:52:41:53:20:e0:3f:49:a1:d4:aa:00:00:09:00:00:00
> 
> There are also syslog messages of "abandoning lease to e0:3f:49:a1:d4:aa
> of 192.168.219.4" which I don't get at all.
> 
> 

Are you dual-booting Kermit, or netbooting it, or doing anything else
which may cause it to run more than one DHCP client? From the
information given it looks like the host with MAC address
e0:3f:49:a1:d4:aa is presenting two different client-ids at different
times. Since client-id trumps MAC address as a unique host identifier,
that could explain what's going on. (the client-id is the last field in
the leases database).

Setting log-dhcp and posting the logs showing this sort of thing
happening would be useful.

Cheers,

Simon.


> 
> 
> On 29/04/16 12:27, Kevin Darbyshire-Bryant wrote:
>>
>> Hi All,
>>
>>
>> I've just noticed some strange/different behaviour with regard to
>> dhcpv6 address allocation.  I've a couple of 'internal' machines that
>> I'd like to have fixed ip addresses.  To that end, and it used to work
>> I've got lines similar to: 
>> dhcp-host=E0:3F:49:A1:D4:AA,192.168.219.4,[::0:4],Kermit   - In theory
>> kermit gets 192.168.219.4 and the ipv6 address 'constructed prefix::0:4'
>>
>>
>> Instead, these lines appear to be partially ignored with the host
>> getting the usual pseudo random address constructed from the ipv6
>> prefix/range.  An nslookup pointing to dnsmasq does return the '0:4'
>> address, unfortunately that's not the address handed out by dhcp.  
>> I'm also seeing ' abandoning lease to e0:3f:49:a1:d4:aa of
>> 192.168.219.4' type warnings which is odd.  Also the entry in the
>> leases database looks odd to me: 1461971298 e0:3f:49:a1:d4:aa
>> 192.168.219.4 Kermit
>> 01:52:41:53:20:e0:3f:49:a1:d4:aa:00:00:09:00:00:00 - that almost looks
>> like an ipv6 type entry.
>>
>>
>> Confused!
>>
>>
>> Kevin
>>
>>
>>
>> _______________________________________________
>> Dnsmasq-discuss mailing list
>> Dnsmasq-discuss at lists.thekelleys.org.uk
>> http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> 
> 
> 
> 
> _______________________________________________
> Dnsmasq-discuss mailing list
> Dnsmasq-discuss at lists.thekelleys.org.uk
> http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
>