Option 52
The Option Overload option, indicating that DHCP options also appear in the BOOTP file or server-name fields because the normal options area was insufficient.
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Browse the glossaryDHCPv4 glossary — page 2
45 definitions associated with DHCPv4.
Browse DHCPv4 definitions
45 matching terms
Page 2 of 2Option 53
The DHCP Message Type option, identifying messages such as DISCOVER, OFFER, REQUEST, DECLINE, ACK, NAK, RELEASE, and INFORM.
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The Server Identifier option, normally containing the selected DHCP server's IPv4 address. Clients use it to identify which offer they accepted and where unicast requests should go.
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The Parameter Request List, an ordered list of option codes the client asks the server to provide. Its contents and ordering are often used for DHCP fingerprinting.
Read definitionOption 60
The Vendor Class Identifier option, used by a client to identify its vendor type, device family, or boot environment. Servers can match it to apply vendor-specific policy.
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The Client Identifier option, used to identify a client independently of the BOOTP hardware-address field. Servers should apply consistent identity rules to avoid duplicate leases.
Read definitionOption 66
The TFTP Server Name option, historically used to tell a booting client where to obtain files. Modern environments may use other boot-server or URL options.
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The Bootfile Name option, identifying the initial file a network-boot client should request. The value depends on architecture, firmware, and provisioning system.
Read definitionOption 77
The User Class option, which lets a client present one or more administrator-defined class values. Servers can use it for policy and option selection.
Read definitionOption 81
The Client FQDN option, used to communicate a client's FQDN and dynamic DNS update preferences. It supports coordinated ownership of A and PTR updates.
Read definitionOption 82
The Relay Agent Information option, added by a relay or access device to identify circuit, subscriber, remote device, link selection, or other access context. Servers use its suboptions for policy and address selection.
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The DHCP Authentication option. Deployment is limited, and network-layer controls such as DHCP snooping are more common in enterprise access networks.
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The Client System Architecture Type option, used by PXE and network boot systems to select a boot program appropriate for BIOS, UEFI, x86, ARM, and other architectures.
Read definitionRelay Agent Information option
The full name of DHCP option 82. Its suboptions can identify circuit, remote device, subscriber, link selection, and other relay-supplied context.
Read definitionRemote ID
An option 82 suboption identifying the remote access device, subscriber unit, or relay context. The exact value format is implementation-specific.
Read definitionRenewing state
The client state entered at T1 when it attempts to renew its lease directly with the original server. If renewal fails until T2, the client enters REBINDING.
Read definitionRouter option
DHCP option 3, which supplies one or more default gateway addresses in order of preference. It should not be confused with classless static route option 121.
Read definitionSIADDR
The BOOTP/DHCP "next server" address field, historically used to identify a server involved in the client's bootstrap process. Modern DHCP boot behavior may instead use options.
Read definitionSubnet selection option
An option that lets a client or relay identify the subnet from which an address should be selected when GIADDR or the receiving interface is insufficient.
Read definitionXID
The transaction identifier in the BOOTP/DHCPv4 header used to match client and server messages. It is selected by the client and repeated through the exchange.
Read definitionYIADDR
The "your IP address" field in a BOOTP/DHCPv4 reply, containing the IPv4 address offered or assigned to the client when applicable.
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