Connectivity Guide

Figure 3. DHCP Packet Format
The table shows common options using DHCP packet formats.
DHCP Option Description
Subnet mask 1 — Subnet mask of the client
Router 3 — Router IP addresses that serve as the default gateway for the client
Domain name server 6 — Domain name servers (DNS) that are available to the client
Domain name 15 — Domain name that clients use to resolve hostnames via DNS
IP address lease time 51 — Amount of time that the client uses an assigned IP address
DHCP message type 53:
• 1 — DHCPDISCOVER
• 2 — DHCPOFFER
• 3 — DHCPREQUEST
• 4 — DHCPDECLINE
• 5 — DHCPACK
• 6 — DHCPNACK
• 7 — DHCPRELEASE
• 8 — DHCPINFORM
Parameter request
list
55 — Parameters the server requires for DHCP clients. This is a series of octets where each octet is a DHCP
option code
Renewal time 58 — Amount of time, after the IP address is granted, that the client attempts to renew its lease with the original
server
Rebinding time 59 — Amount of time, after the IP address is granted, that the client attempts to renew its lease with any server, if
the original server does not respond
Vendor class
identier
60 — User-dened string the Relay Agent uses to forward DHCP client packets to a specic DHCP server
User port stacking 230 — Stacking option variable that provides the DHCP server stack-port details when the DHCP oer is set
End 255 — Signal of the last option in the DHCP packet
DHCP server
The Dynamic Host Conguration Protocol (DHCP) server provides network conguration parameters to DHCP clients on request. A DHCP
server dynamically allocates four required IP parameters to each computer on the virtual local area network (VLAN) — the IP address,
System management
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