Choosing an open source DHCPv6 client

[Vikram Agrawal]

Thanks...That worked.

I needed it for server - client mapping for specific configurations.
The ISC DHCPv6 server could have specific prefixes/addresses allocated to
the client with the given duid.
Normally the client duid is auto generated based on the LL or LLT. So the
server has no way of knowing it until of course it reads the client leases
file.

So I just required to have  (duid) configuration manually specified at the
client end and use the same config (duid) at server end to allocated
specific prefixes for the client.


Is there any better way of doing it ?

Regards,
Vikram





-----Original Message-----
From: Bjørn Mork [mailto:bjorn at mork.no]
Sent: 19 October 2011 15:39
To: Vikram Agrawal
Cc: ipv6-ops at lists.cluenet.de
Subject: Re: Choosing an open source DHCPv6 client

Vikram Agrawal <vikram.agrawal at ipinfusion.com> writes:

> Thanks for the inputs.
> I have stuck to using ISC DHCP client.
>
> But there's another thing which I figured was not working on ISC DHCP
> Client which is;
>
> ISC DHCP Client - Does not pick up the cilent duid from config file.
>
> isc-dhclient-4.1.1-P1 did not allow for any duid specific
> configuration on the command line.
> Dhclient - isc-dhclient-4.2.2 is better in the sense that it provides
> an option -D to pick up either the LL or LLD.
> The DUID taken is either the LL ( link layer) or the LLT (link layer
> with timestamp).
>
> The dhclient.conf file states that the duid could be provided with a
> send dhcp-client-identifier <address>

It does?  Not in mine.  dhcp-client-identifier is a DHCP option.  The
DHCPv6 client DUID option name is dhcp6.client-id. But configuring it is not
supported.  From dhcp-options(5):

     option dhcp6.client-id string;

         This option specifies the client's DUID identifier.  DUIDs are
         similar but different from DHCPv4 client identifiers - there
         are documented duid types:

         duid-llt

         duid-en

         duid-ll

         This value should not be configured, but rather is provided by
         clients and treated as an opaque identifier key blob by
         servers.



Anyway, supported or not, I just tested setting

 send dhcp6.client-id 0:1:0:1:16:31:5b:6e:2:0:a:b:c:d;

in dhclient.conf and it does work as expeced.  You should be careful,
though.  The DUID scheme is created to ensure unique IDs, and configuring
them are guaranteed to screw up this at some point...

Why can't you use the standard LL or LLD scheme?


Bjørn