[Kea-users] Set domain-search option for dhcp4

[Francis Dupont]

Olivier Clavel writes:
> After reading the RFC (https://tools.ietf.org/search/rfc3397) and
> struggling a bit, here is how to work around the problem until the future
> enhancement is developed (see ticket below). Please read the rfc if you
> need more than one domain. Example below for a single one.
> 
> 1 - convert string to hex (conversion tool here:
> http://www.swingnote.com/tools/texttohex.php)
> 
> e  x  a  m  p  l  e  .  c  o  m
> 65 78 61 6d 70 6c 65 2e 63 6f 6d
> 
> 2 - drop the dots, prepend each element with number of chars and finish
> with null
> 7) e  x  a  m  p  l  e  3) c  o  m  (null)
> 07 65 78 61 6d 70 6c 65 03 63 6f 6d 00

=> it is DNS wire format, the last 00 stands for the trailing dot.
 BTW it can be represented in DHCPv4 by a tuple array (cf Kea 1.2
ticket #4070, I note to add this in unit tests) if it is not
compressed (compression is explicitly allowed in this option
which BTW has for format an array of DNS names).
 The DNS names (aka FQDNs) in wired format are supposed to be supported
by Kea but it seems only DHCPv6 standard options use it. So please
open a ticket.

Thanks

Francis Dupont <fdupont at isc.org>