[Dnsmasq-discuss] IPv6 dhcp strangeness

[Simon Kelley]

On 03/05/16 18:48, Kevin Darbyshire-Bryant wrote:
> Hi Simon,
> 
> Thanks for getting back to me.  Kermit is a Windows Home Server box and
> is definitely not net or dual booted.  Here's the relevant 'log dhcp'
> extract from a clean boot of it. 
> 
> dhcp-host=id:00:01:00:01:1b:75:4c:36:e0:3f:49:a1:d4:aa,[::4],Kermit
> dhcp-host=E0:3F:49:A1:D4:AA,192.168.219.4,kermit
> 
> Before booting:
> 
> nslookup kermit
> nslookup: can't resolve '(null)': Name does not resolve
> 
> Name:      kermit
> Address 1: 2001:470:183f:da2b::4 kermit.darbyshire-bryant.me.uk
> Address 2: 192.168.219.4 kermit.darbyshire-bryant.me.uk
> 
> No entries in dhcp.leases.
> 
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> available DHCP range: 192.168.219.2 -- 192.168.219.253
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> vendor class: MSFT 5.0
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> client provides name: Kermit
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> DHCPREQUEST(br-lan) 192.168.219.4 e0:3f:49:a1:d4:aa
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> tags: lan, known, br-lan
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> DHCPACK(br-lan) 192.168.219.4 e0:3f:49:a1:d4:aa kermit
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> requested options: 1:netmask, 15:domain-name, 3:router, 6:dns-server,
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> requested options: 44:netbios-ns, 46:netbios-nodetype, 47:netbios-scope,
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> requested options: 31:router-discovery, 33:static-route,
> 121:classless-static-route,
> Tue May  3 18:40:57 2016 daemo> 
> Dnsmasq-discuss mailing list
> Dnsmasq-discuss at lists.thekelleys.org.uk
> http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> 

>> _______________________________________________
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>
>
>
> _______________________________________________
n.info dnsmasq-dhcp[2862]: 1035611837
> requested options: 249, 43:vendor-encap
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 next
> server: 192.168.219.1
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837
> broadcast response
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  1 option: 53 message-type  5
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  4 option: 54 server-identifier  192.168.219.1
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  4 option: 51 lease-time  12h
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  4 option: 58 T1  6h
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  4 option: 59 T2  10h30m
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  4 option:  1 netmask  255.255.255.0
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  4 option: 28 broadcast  192.168.219.255
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  4 option:  3 router  192.168.219.1
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  4 option:  6 dns-server  192.168.219.1
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size: 23 option: 15 domain-name  darbyshire-bryant.me.uk
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size: 33 option: 81 FQDN  03:ff:ff:6b:65:72:6d:69:74:2e:64:61:72:62...
> Tue May  3 18:40:57 2016 daemon.info dnsmasq-dhcp[2862]: 1035611837 sent
> size:  4 option: 44 netbios-ns  192.168.219.1
> Tue May  3 18:40:58 2016 daemon.info dnsmasq-dhcp[2862]: 9972055
> available DHCP range: 2001:470:183f:da2b::2 -- 2001:470:183f:da2b::ffff:ffff
> Tue May  3 18:40:58 2016 daemon.info dnsmasq-dhcp[2862]: 9972055 vendor
> class: 311
> Tue May  3 18:40:58 2016 daemon.info dnsmasq-dhcp[2862]: 9972055
> DHCPCONFIRM(br-lan) 00:01:00:01:1b:75:4c:36:e0:3f:49:a1:d4:aa
> Tue May  3 18:40:58 2016 daemon.info dnsmasq-dhcp[2862]: 9972055
> DHCPREPLY(br-lan) 2001:470:183f:da2b::9f93:7b6a
> 00:01:00:01:1b:75:4c:36:e0:3f:49:a1:d4:aa Kermit
> Tue May  3 18:40:58 2016 daemon.info dnsmasq-dhcp[2862]: 9972055 tags:
> known, dhcpv6, br-lan
> Tue May  3 18:40:58 2016 daemon.info dnsmasq-dhcp[2862]: 9972055 sent
> size: 14 option:  1 client-id  00:01:00:01:1b:75:4c:36:e0:3f:49:a1:d4:aa
> Tue May  3 18:40:58 2016 daemon.info dnsmasq-dhcp[2862]: 9972055 sent
> size: 14 option:  2 server-id  00:01:00:01:1e:b7:72:d8:14:cc:20:be:89:33
> Tue May  3 18:40:58 2016 daemon.info dnsmasq-dhcp[2862]: 9972055 sent
> size: 29 option: 13 status  0 all addresses still on link
> 
> Only Entry in dhcp.leases related to kermit
> 
> 1462340457 e0:3f:49:a1:d4:aa 192.168.219.4 kermit 01:e0:3f:49:a1:d4:aa
> 
> Kermit thinks it has 2001:470:183f:da2b::9f93:7b6a as per the dhcp
> reply, which is fair enough but I don't understand why the UID was
> ignored.  Also, nslookup replies from dnsmasq still only return the
> configured addresses for kermit and no sign of the dhcpv6 allocated one.
> 
> Ideas?
> 

Yes, combine the dhcp-host lines


dhcp-host=id:00:01:00:01:1b:75:4c:36:e0:3f:49:a1:d4:aa,[::4],E0:3F:49:A1:D4:AA,192.168.219.4,Kermit

(should be one line, stupid mail client wrapped it.)

I'll try and work out how having two possibly matching dhcp-host lines
has confused dnsmasq, but in the meantime, that stands a good chance of
fixing things, and it how it was designed to be done.


(Since the DHCPv6 code knows about MAC addresses, you could miss out the
id: section as well, if that makes things easier.

Cheers,

Simon.