Deployment Guide

The following table lists common DHCP options.
Option Number and Description
Subnet Mask Option 1
Specifies the client’s subnet mask.
Router Option 3
Specifies the router IP addresses that may serve as the client’s default gateway.
Domain Name
Server
Option 6
Specifies the domain name servers (DNSs) that are available to the client.
Domain Name Option 15
Specifies the domain name that clients should use when resolving hostnames via DNS.
IP Address Lease
Time
Option 51
Specifies the amount of time that the client is allowed to use an assigned IP address.
DHCP Message
Type
Option 53
● 1: DHCPDISCOVER
● 2: DHCPOFFER
● 3: DHCPREQUEST
● 4: DHCPDECLINE
● 5: DHCPACK
● 6: DHCPNACK
● 7: DHCPRELEASE
● 8: DHCPINFORM
Parameter
Request List
Option 55
Clients use this option to tell the server which parameters it requires. It is a series of octets where each
octet is DHCP option code.
Renewal Time Option 58
Specifies the amount of time after the IP address is granted that the client attempts to renew its lease
with the original server.
Rebinding Time Option 59
Specifies the 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
Identifer
Option 60
Identifies a user-defined string used by the Relay Agent to forward DHCP client packets to a specific
server.
L2 DHCP
Snooping
Option 82
Specifies IP addresses for DHCP messages received from the client that are to be monitored to build a
DHCP snooping database.
User Port
Stacking
Option 230
Set the stacking option variable to provide DHCP server stack-port detail when the DHCP offer is set.
End Option 255
Signals the last option in the DHCP packet.
Dynamic Host Configuration Protocol (DHCP) 245