Fingerprint
A pattern of observable behavior used to infer device type, software, or activity. DHCP option order, DNS query patterns, EDNS support, and TTL behavior can contribute to a fingerprint.
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Browse the glossaryDHCP glossary — page 3
97 definitions associated with DHCP.
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97 matching terms
Page 3 of 5Fixed address
A configured mapping that assigns a specific IP address to a matching client, commonly based on MAC address, client identifier, or DUID. In Infoblox terminology, a fixed address is a managed object distinct from a DHCP reservation.
Read definitionHigh-water mark
A configured or observed utilization threshold indicating that an address pool or resource is approaching exhaustion. Alerts should leave enough time to expand, reclaim, or redesign the pool.
Read definitionHold-down timer
A waiting period during which a resource, route, lease, or state transition is not immediately reused or reversed. Hold-downs reduce flapping and allow stale information to age out.
Read definitionHot standby
A DHCP failover mode in which one server normally owns most or all active service while the partner is ready to take over. It is often chosen when servers are in separate sites or one is intended mainly for disaster recovery.
Read definitionHTTPBoot
A network boot method that retrieves boot resources using HTTP or HTTPS instead of TFTP. DHCP options identify client architecture and provide a boot URI or discovery information.
Read definitionIP helper
A router or switch feature that forwards selected UDP broadcasts, most commonly DHCPv4, to configured server addresses. Because some implementations forward multiple UDP services, the exact configuration should be reviewed.
Read definitionKea
An open-source DHCPv4, DHCPv6, and dynamic DNS server developed by ISC. It uses a modular architecture, APIs, hooks, and external database options.
Read definitionLease
The time-bounded right for a client to use an address or prefix and associated configuration. Lease state is maintained by both client and server.
Read definitionLease database
The server data store containing lease bindings, states, identities, and timing. Backup, replication, integrity, and recovery of this database are central to DHCP availability.
Read definitionLease duration
The amount of time an address or prefix remains valid before renewal or expiration. Short leases increase churn and server traffic, while long leases slow reclamation and configuration change.
Read definitionLease history
A record of past address-to-client associations and state changes. It supports troubleshooting, security attribution, capacity analysis, and compliance retention.
Read definitionLease reclamation
The process of returning expired, released, or administratively cleared addresses to an available state. Reclamation may include grace periods, conflict checks, DNS cleanup, and history retention.
Read definitionLeasequery
A protocol family that allows authorized systems to request current or historical binding information from DHCP servers. It is used by relays, access concentrators, security platforms, and IPAM systems.
Read definitionLoad balance
A failover mode or traffic design in which multiple servers actively handle clients according to a hash, split, relay selection, or load balancer. For DHCP, shared lease state and consistent client handling are critical.
Read definitionLow-water mark
A threshold indicating that available address capacity has fallen below a desired reserve. It can trigger alerts, expansion, or automated allocation from a parent block.
Read definitionMAC address
A link-layer hardware address, commonly 48 bits on Ethernet. DHCPv4 often uses it as part of client identity, but it can be changed, duplicated, or hidden behind relays.
Read definitionManual allocation
An allocation method in which an administrator preassigns a specific address to a client and DHCP communicates that assignment. It is commonly implemented through reservations or fixed mappings.
Read definitionMaximum client lead time (MCLT)
A DHCP failover safety interval limiting how far one partner can extend a lease beyond information known to the other. It reduces the chance of duplicate allocation after communication or partner failure.
Read definitionMicrosoft DHCP
The Windows Server DHCP role for IPv4 and IPv6 configuration, scopes, reservations, policies, authorization, DNS updates, and DHCPv4 failover. Management is available through GUI, PowerShell, and APIs.
Read definitionNext-server
A DHCP or BOOTP field or configuration identifying the server from which a client should obtain boot resources. It is commonly paired with a boot filename or URL.
Read definitionOption code
The numeric identifier assigned to a DHCP option. DHCPv4 and DHCPv6 have separate option-code registries and encoding rules.
Read definitionOption space
A namespace or grouping that defines how option codes and suboptions are interpreted. Products may support standard, vendor, relay, site-specific, or custom option spaces.
Read definitionPAD option
A zero-length or padding option used to align or fill option areas without conveying configuration. DHCPv4 option 0 is Pad.
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