This chapter covers
- How Dynamic Host Configuration Protocol (DHCP) automates the configuration of network hosts
- Configuring Cisco IOS devices as DHCP servers and clients
- Using DHCP relay to enable centralized DHCP servers
- Viewing IP settings on Windows, macOS, and Linux
Dynamic Host Configuration Protocol (DHCP) is a protocol that automates the assignment of IP addresses, default gateways, and other network configuration information to hosts. But what exactly is a host? A host is any device that sends and receives packets over a network—put in other terms, any device with an IP address. Manually configuring thousands (or tens of thousands) of hosts in a large network is simply not feasible. Even in a small network—for example, a home network—automating host configuration makes using the network much simpler for end users who might not be tech savvy (or even if they are, would rather not have to manually configure all of their devices).
Hosts can also include network infrastructure devices like routers and switches—as we’ll see in the next chapter on Secure Shell (SSH), even a Layer 2 switch can have an IP address to allow remote management. However, DHCP is most often used to automate the configuration of end hosts, such as PCs, smartphones, tablets, etc., and is almost ubiquitous in modern networks. In this chapter, we will cover the following CCNA exam topics: