What is the maximum length for a Domain Name System (DNS) domain name?

The maximum length for a Domain Name System (DNS) domain name is 255 bytes. This limitation is established by the DNS protocol, which was outlined in various Internet Engineering Task Force (IETF) documents, specifically RFC 1035. In a DNS domain name, each label (the segments between dots) can be up to 63 bytes long, and the total length of the entire domain name—including all labels and the separators (dots)—cannot exceed 255 bytes.

The byte limit is crucial for ensuring efficient and standardized processing of DNS queries across various networking systems. It allows for a significant number of unique domain names while maintaining a manageable size for data transmission.

In contrast, the other options represent larger sizes than what's defined by the RFCs, which makes them invalid choices for the maximum DNS domain name length. Understanding this limitation helps in domain name creation and ensures compatibility with DNS standards.