1-4Figure 1-2 DHCP packet formatThe fields are described as follows:z op: Operation types of DHCP packets, 1 for request packets and 2 for response packets.z htype, hlen: Hardware address type and length of the DHCP client.z hops: Number of DHCP relay agents which a DHCP packet passes. For each DHCP relay agentthat the DHCP request packet passes, the field value increases by 1.z xid: Random number that the client selects when it initiates a request. The number is used toidentify an address-requesting process.z secs: Elapsed time after the DHCP client initiates a DHCP request.z flags: The first bit is the broadcast response flag bit, used to identify that the DHCP responsepacket is a unicast (set to 0) or broadcast (set to 1). Other bits are reserved.z ciaddr: IP address of a DHCP client.z yiaddr: IP address that the DHCP server assigns to a client.z siaddr: IP address of the DHCP server.z giaddr: IP address of the first DHCP relay agent that the DHCP client passes after it sent therequest packet.z chaddr: Hardware address of the DHCP client.z sname: Name of the DHCP server.z file: Path and name of the boot configuration file that the DHCP server specifies for the DHCPclient.z option: Optional variable-length fields, including packet type, valid lease time, IP address of a DNSserver, and IP address of the WINS server.Protocol SpecificationProtocol specifications related to DHCP include:z RFC2131: Dynamic Host Configuration Protocolz RFC2132: DHCP Options and BOOTP Vendor Extensionsz RFC1542: Clarifications and Extensions for the Bootstrap Protocol
