Option dhcp6.client-linklayer-addr

Antonios Atlasis antonios.atlasis at gmail.com
Tue Feb 3 19:48:35 UTC 2015


Thank you very much Espen for your response.

Well,. the client linklayer address option is not encapsulated in the
dhcpb6 request, but directly into the dhcpb6 relay message, because, as the
RFC 6939 specifies, it is added by the Relay server and not by the client
itself. I am attaching a pcap if someone wants to have a look at it.

Nevertheless, I will give it a try tomorrow at the lab and I'll let you
know.

Thanks again

Antonios

On 3 February 2015 at 20:45, Espen Tallaksen <espen.tallaksen at gmail.com>
wrote:

> Hi
>
> At least you will need to extract the dhcp-request from the relayed
> dhcp-packet as it's kind of encapsulated by the relay-agent. You will find
> an example below:
>
> v6relay(1, (binary-to-ascii(16, 8, ":", option docsis.cm-mac-address)));
>
> v6relay(1, something) 1 refers to the first relay-agent in the chain.
>
> Obviously, you will neew to replace docsis-things with your stuff. I have
> never tried dhcp6.client-linklayer-addr though. Hope it will help you out.
>
>
> Best regards
>
> Espen Tallaksen
>
>
> On 3 Feb 2015 18:21, "Antonios Atlasis" <antonios.atlasis at gmail.com>
> wrote:
>
>> Hi,
>>
>> I have setup a DHCPv6 relay which forwards the DHCPv6 request to my ISC
>> DHCPv6 server version 4.3.1 running on Centos 6.6.
>>
>> The DHCPv6 server leases an address successfully to the client.
>>
>> I have confirmed by using wireshark  that the DHCPv6 Relay includes the
>> Option 79 (Client Link-Layer Address) defined in RFC6939 in its
>> Relay-Forward messages.
>>
>> I want to log the MAC address of the client by using the
>> dhcp6.client-linklayer-addr which seems to be implemented in this version
>> of ISC DHCP (I am saying "it seems" because it is included here:
>> https://deepthought.isc.org/article/AA-01112/0/Newly-Pre-defined-Options-in-DHCP-4.3.html
>> but not in the official documentation).
>>
>> In my dhcpd.conf I have tried several configurations, including the one
>> described here:
>> https://www.mail-archive.com/dhcp-users@lists.isc.org/msg00622.html
>> that is:
>>
>> if (exists dhcp6.client-linklayer-addr) {
>>         log(info,"option dhcp6.client-linklayer-addr present");
>> } else {
>>        log(info,"option dhcp6.client-linklayer-addr not present");
>> }
>>
>> but I also get
>>
>> dhcpd: option dhcp6.client-linklayer-addr not present
>>
>> Does anyone know if this option is implemented indeed and if so, what I
>> am possibly missing? Any suggestions?
>>
>> Thanks
>>
>> Antonios
>>
>> _______________________________________________
>> dhcp-users mailing list
>> dhcp-users at lists.isc.org
>> https://lists.isc.org/mailman/listinfo/dhcp-users
>>
>
> _______________________________________________
> dhcp-users mailing list
> dhcp-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/dhcp-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/dhcp-users/attachments/20150203/cba35bac/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dhcpv6relay-ISC-Ubuntu1404.pcap
Type: application/vnd.tcpdump.pcap
Size: 1580 bytes
Desc: not available
URL: <https://lists.isc.org/pipermail/dhcp-users/attachments/20150203/cba35bac/attachment.bin>


More information about the dhcp-users mailing list