RFC 3442 (rfc3442) - Page 3 of 9

The Classless Static Route Option for Dynamic Host Configuration Protocol (DHCP) version 4

RFC 3442        Classless Static Route Option for DHCPv4   December 2002


   This document also uses the following terms:

      "DHCP client"

         DHCP client or "client" is an Internet host using DHCP to
         obtain configuration parameters such as a network address.

      "DHCP server"

         A DHCP server or "server" is an Internet host that returns
         configuration parameters to DHCP clients.

      "link"

         Any set of network attachment points that will all receive a
         link-layer broadcast sent on any one of the attachment points.
         This term is used in DHCP because in some cases more than one
         IP subnet may be configured on a link.  DHCP uses a local-
         network (all-ones) broadcast, which is not subnet-specific, and
         will therefore reach all nodes connected to the link,
         regardless of the IP subnet or subnets on which they are
         configured.

         A "link" is sometimes referred to as a broadcast domain or
         physical network segment.

Classless Route Option Format

   The code for this option is 121, and its minimum length is 5 bytes.
   This option can contain one or more static routes, each of which
   consists of a destination descriptor and the IP address of the router
   that should be used to reach that destination.

    Code Len Destination 1    Router 1
   +-----+---+----+-----+----+----+----+----+----+
   | 121 | n | d1 | ... | dN | r1 | r2 | r3 | r4 |
   +-----+---+----+-----+----+----+----+----+----+

    Destination 2       Router 2
   +----+-----+----+----+----+----+----+
   | d1 | ... | dN | r1 | r2 | r3 | r4 |
   +----+-----+----+----+----+----+----+

   In the above example, two static routes are specified.







Lemon, et. al.              Standards Track