Non-Octet Boundary Delegation (RFC 4183)

Станислав ginermail at
Wed Sep 21 19:38:02 UTC 2011


Could anyone tell me if ISC DHCP supports Non-Octet Boundary
Delegation? It supports by ISC BIND as I see but I've not managed to
find the same information related to the DHCP server.

Cut from
3.  Non-Octet Boundary Delegation

   In RFC 2317, there is no mechanism for non-octet boundary delegation.
   Networks would be represented as being part of the domain of the next

   Examples:  -> -> ->

   In the event that the entity subnetting does not actually own the
   network being subnetted on an octet break, a mechanism needs to be
   available to allow for the specification of those subnets.  The
   mechanism is to allow the use of maskedoctet labels as delegation

   For example, consider an entity A that controls a network  Entity A delegates to entity B the network
   In order to avoid having to update entries for entity B whenever
   entity B updates subnetting, entity A delegates the domain (with an NS record in A's DNS tables as
   usual) to entity B.  Entity B then subnets off  It would
   provide a domain name for this network of (in B's DNS tables).

   In order to speak about the non-octet boundary case more easily, it
   is useful to define a few terms.

   Network domain names that do not contain any maskedoctets after the
   first (leftmost) label are hereafter referred to as canonical domain
   names for that network.  is the canonical
   domain name for the network

   Network domain names that do contain maskedoctet labels after the
   first (leftmost) label can be reduced to a canonical domain name by
   dropping all maskedoctet labels after the first (leftmost) label.
   They are said to be reducible to the canonical network domain name.
   So for example  is reducible to  Note that a network domain name represents
   the same network as the canonical domain name to which it can be


More information about the dhcp-users mailing list