Reference Guide

Option Number and Description
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
Identifiers 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.
222