Dynamic Host Configuration Protocol (DHCP)

What is DHCP?

Dynamic Host Configuration Protocol (DHCP) is a standardized network protocol used on Internet Protocol (IP) networks.The DHCP is controlled by a DHCP server that dynamically distributes network configuration parameters for interfaces and services. Networks ranging in size from small home networks to campus networks frequently use DHCP.

Here's an example of troubleshooting DHCP issues in a small home network using wire data for real-time visibility into rogue server behavior.

How does DHCP work?

Based on the Bootstrap Protocol (BOOTP) released in 1985, DHCP differs from BOOTP in that it can dynamically allocate IP addresses from a pool and reclaim them when they are no longer in use.

A DHCP server can manage TCP/IP settings for devices on a network by automatically, dynamically, or manually assigning them IP addresses:

Dynamic: a Network Admin reserves a set number of IP addresses and each DHCP client on the LAN is configured to request an IP address from the server during network initialization.

Automatic: Similar to Dynamic, but the DHCP server keeps a list of previous IP address assignments in order to assign a client the same IP addresses as in the past.

Manual: Based on parameters defined by the administrator, the DHCP server issues a private IP address dependent on each client's individual MAC address. If no match is found, the network can fall back on either Dynamic or Automatic protocol.