RFC 3396 (rfc3396) - Page 2 of 9
Encoding Long Options in the Dynamic Host Configuration Protocol (DHCPv4)
Alternative Format: Original Text Document
RFC 3396 Encoding Long Options in DHCPv4 November 2002
However, in some cases it may be useful to send options that are
longer than 255 bytes. RFC 2131 [3] specifies that when more than
one option with a given type code appears in the DHCP packet, all
such options should be concatenated together. It does not, however,
specify the order in which this concatenation should occur.
We specify here the ordering that MUST be used by DHCP protocol
agents when sending options with more than 255 bytes. This method
also MUST be used for splitting options that are shorter than 255
bytes, if for some reason the encoding agent needs to do so. DHCP
protocol agents MUST use this method whenever they receive a DHCP
packet containing more than one occurrence of a certain type of
option.
2. Terminology
DHCP
Throughout this document, the acronym "DHCP" is used to refer to
the Dynamic Host Configuration Protocol as specified in RFC 2131
[3] and RFC 2132 [4].
DHCPv4
We have used the term "DHCPv4" in the abstract for this document
to distinguish between the DHCP protocol for IPv4 as defined in
RFC 2131 and RFC 2132 and the DHCP protocol for IPv6, which, at
the time that this document was written, was still under
development.
DHCP protocol agents
This refers to any device on the network that sends or receives
DHCP packets - any DHCP client, server or relay agent. The nature
of these devices is not important to this specification.
Encoding agent
The DHCP protocol agent that is composing a DHCP packet to send.
Decoding agent
The DHCP protocol agent that is processing a DHCP packet it has
received.
Options
DHCP options are collections of data with type codes that indicate
how the options should be used. Options can specify information
that is required for the DHCP protocol, IP stack configuration
parameters for the client, information allowing the client to
rendezvous with DHCP servers, and so on.
Lemon & Cheshire Standards Track