What Is DHCP?
DHCP (Dynamic Host Configuration Protocol) automatically assigns IP addresses, subnet masks, gateways, and DNS settings to devices when they join a network — no manual configuration required.
The DORA Handshake
Discover
The client broadcasts a request for an IP address.
Offer
The DHCP server offers an available address from its pool.
Request
The client requests the offered address.
Acknowledge
The server confirms and records the lease.
DHCP in the Data Center
At data center scale, manual IP assignment does not work. DHCP keeps thousands of servers, management interfaces, and appliances addressable — but a dynamic lease is only useful if operations can still tie an address back to a specific physical device, rack, and owner.
Common Questions About DHCP
What port does DHCP use?
DHCP uses UDP ports 67 and 68: the server listens on port 67 and the client receives on port 68. DHCPv6 uses UDP ports 546 (client) and 547 (server).
What is a DHCP lease time?
The lease time is how long a client may keep an assigned IP address before it must renew. Short leases suit networks with high device turnover; long leases reduce renewal traffic on stable networks like data centers.
What is a DHCP reservation?
A reservation permanently maps a device's MAC address to a specific IP address, so it always receives the same address from the DHCP server. It combines the reliability of static addressing with central DHCP management — common for servers, printers, and BMC management interfaces.
DHCP vs static IP — which should you use?
Use DHCP (or DHCP reservations) for most devices so addressing stays centrally managed and conflict-free. Use static IPs only where a device must work even if the DHCP server is unreachable — such as the DHCP server itself, core switches, and out-of-band management interfaces.
What is DHCP snooping?
DHCP snooping is a switch security feature that blocks rogue DHCP servers. The switch only forwards DHCP offers from trusted ports, preventing attackers or misconfigured devices from handing out bad addresses.
What is the difference between DHCP and DNS?
DHCP assigns IP addresses to devices; DNS translates names into IP addresses. They work together — and in a DDI platform they are managed together so records never drift apart.
From dynamic address to real device context
Sensaka links every address to its hardware, health, and business service — so a DHCP lease becomes a device you can actually operate.