RFC 1048 (rfc1048) - Page 2 of 7
BOOTP vendor information extensions
Alternative Format: Original Text Document
RFC 1048 BOOTP Extensions February 1988
One obvious advantage of this procedure is the centralized management
of network addresses, which eliminates the need for per-host unique
configuration files. In an environment with several hundred hosts,
maintaining local configuration information and operating system
versions specific to each host might otherwise become chaotic. By
categorizing hosts into classes and maintaining configuration
information and boot programs for each class, the complexity of this
chore may be reduced in magnitude.
BOOTP Vendor Information Format
The full description of the BOOTP request/reply packet format may be
found in [RFC-951]. The rest of this document will concern itself
with the last field of the packet, a 64 octet area reserved for
vendor information, to be used in a hitherto unspecified fashion. A
generalized use of this area for giving information useful to a wide
class of machines, operating systems, and configurations follows. In
situations where a single BOOTP server is to be used among
heterogeneous clients in a single site, a generic class of data may
be used.
Vendor Information "Magic Cookie"
As suggested in [RFC-951], the first four bytes of this field have
been assigned to the magic cookie, which identifies the mode in
which the succeeding data is to be interpreted. The value of the
magic cookie is the 4 octet dotted decimal 99.130.83.99 (or
hexadecimal number 63.82.53.63) in network byte order.
Format of Individual Fields
The vendor information field has been implemented as a free
format, with extendable tagged sub-fields. These sub-fields are
length tagged (with exceptions; see below), allowing clients not
implementing certain types to correctly skip fields they cannot
interpret. Lengths are exclusive of the tag and length octets;
all multi-byte quantities are in network byte-order.
Fixed Length Data
The fixed length data are comprised of two formats. Those that
have no data consist of a single tag octet and are implicitly
of one-octet length, while those that contain data consist of
one tag octet, one length octet, and length octets of data.
Pad Field (Tag: 0, Data: None)
May be used to align subsequent fields to word boundaries
Prindeville