DHCP (Dynamic Host Configuration Protocol) is the magic that happens behind the scenes that allows your computer and other devices to automatically configure to connect to the upstream router. The router uses DHCP to assign each device an IP address and tells it what DNS service to use. If your computer and the DHCP server get out of sync, learning how to tell your computer to “Renew DHCP Lease” might be what it takes to fix things. (Rebooting accomplishes the same thing too.)