Which protocol is used to automate IP configuration, including IP address and DNS information?

The protocol that automates IP configuration, including the assignment of IP addresses and DNS information, is Dynamic Host Configuration Protocol (DHCP). DHCP simplifies network management by allowing devices to automatically receive their network configuration parameters from a DHCP server. This process eliminates the need for manual setting of the IP address, subnet mask, gateway, and DNS servers on each device, thus making it easy to manage a network with multiple devices.

When a device connects to a network, it sends a DHCP request to the server. The server then assigns an available IP address and provides the necessary information, which the client uses to communicate on the network. This dynamic allocation of IP addresses is particularly useful in environments with frequently changing devices, such as in home networks or public Wi-Fi.

In contrast, the other protocols do not serve the purpose of automating IP configurations. SMTP (Simple Mail Transfer Protocol) is focused on email transmission, SNMP (Simple Network Management Protocol) is used for managing and monitoring network devices, and ARP (Address Resolution Protocol) is responsible for mapping IP addresses to their corresponding MAC addresses. Thus, DHCP is the correct choice for automating IP configuration tasks.