# 1. General Information

## 1.1 About this Document

This document describes the requirements for name servers and zone data to be met so that DENIC can delegate a domain to those name servers. The policy and the related checks are explained in this document.

## 1.2 Reason

The Domain Name System (DNS) is a hierarchically structured, distributed and replicated database for mapping names in addresses and other Internet infrastructure elements. The hierarchical structure and the distribution are implemented by means of delegation. The root of the namespace is immediately followed by the sub-level of the Top Level Domains (TLDs). The rules for the administration of the TLDs are laid down in the RFC 1591 and other documents. The TLD administrator is responsible for reliable maintenance and care of the zone data in accordance with the latest state of the art and for securing operation of the corresponding name servers according to best practices. Due to its distribution and redundancy the DNS is highly fault-tolerant. Nevertheless, network disturbances and configuration errors may cause a situation in which domains are resolved incorrectly or not at all (refer also to RFC 4697). Although the Internet user will notice the failure, they cannot always identify the DNS as its cause. If the constellation is particularly disadvantageous, DNS failures may trigger disturbances in sections of the network that are neither concerned by the cause nor responsible for it, let alone able to eliminate it. Therefore, the TLD administrators verify prior to delegation that certain requirements are fulfilled in order to guarantee proper functioning of the overall system and reliable service – local and remote - for all requestors from the namespace. Delegation is not implemented, unless all requirements are met. There are a number of additional criteria, which are not absolutely necessary, but which provide an improved service quality, if met.