DHCP or Dynamic Host Configuration Protocol is a protocol that determines and assigns IP addresses for devices on a network. A DHCP server can recognize a device and assign it an IP address automatically. This makes administration easier because the network administrator doesn’t have to manually assign IP addresses every time a device connects to the network. If you use a router in-home network, for example, you’re probably already using DHCP. However, the fact that it has DHCP enabled doesn’t make it a DHCP server.
How Does DHCP Work?
Have you ever used a printer that’s connected to your local network? Are you wondering how it keeps its network assignment? Every device on the network has a MAC address. You can assign a static IP at the server to a specific MAC address. This allows the network printer to always get the same IP even after it reboots and without assigning the IP to the printer. If you print the network configuration at the printer, it will probably tell you that DHCP is enabled and no static IP is assigned. That’s because the IP assignment is handled at the server.
DHCP – Pros and Cons
Aside from being a huge convenience, DHCP is also very reliable. It ensures stability in several ways – periodic renewal, rebinding, and failover. The DHCP clients are given leases that are valid for some time period. The client attempts a lease renewal when half of the lease period has passed. If that server is down for some reason the request will be repeated by the client from time to time as it tries to renew its lease. Security-wise however, DHCP is not as well thought out. It doesn’t contain any mechanism for authentication. This makes it vulnerable to a number of attacks.