Protocol Specification - 3Com 5500-EI PWR Install Manual

htype, hlen: Hardware address type and length of the DHCP client.
hops: Number of DHCP relay agents which a DHCP packet passes. For each DHCP relay agent
that the DHCP request packet passes, the field value increases by 1.
xid: Random number that the client selects when it initiates a request. The number is used to
identify an address-requesting process.
secs: Elapsed time after the DHCP client initiates a DHCP request.
flags: The first bit is the broadcast response flag bit, used to identify that the DHCP response
packet is a unicast (set to 0) or broadcast (set to 1). Other bits are reserved.
ciaddr: IP address of a DHCP client.
yiaddr: IP address that the DHCP server assigns to a client.
siaddr: IP address of the DHCP server.
giaddr: IP address of the first DHCP relay agent that the DHCP client passes after it sent the
request packet.
chaddr: Hardware address of the DHCP client.
sname: Name of the DHCP server.
file: Path and name of the boot configuration file that the DHCP server specifies for the DHCP
client.
option: Optional variable-length fields, including packet type, valid lease time, IP address of a DNS
server, and IP address of the WINS server.

Protocol Specification

Protocol specifications related to DHCP include:
RFC2131: Dynamic Host Configuration Protocol
RFC2132: DHCP Options and BOOTP Vendor Extensions
RFC1542: Clarifications and Extensions for the Bootstrap Protocol
RFC3046: DHCP Relay Agent Information option
1-4