This document and/or information was originally written in Spanish, the official language of Uruguay, the country where LACNIC is legally incorporated and whose laws and regulations LACNIC must meet. Likewise, unofficial information and/or documents are also written in Spanish, as this is the language in which most of LACNIC's collaborators and officers work and communicate. We do our best to ensure that our translations are reliable and serve as a guide for our non-Spanish-speaking members. However, discrepancies may exist between the translations and the original document and/or information written in Spanish. In this case, the original text written in Spanish will always prevail.
Most connections through the Internet use machine names instead of IP addresses. Names are obviously easier to remember than numbers. However, Internet connections between computers connected to this network are made using IP addresses. Therefore, before a connection can be made, the computer's name must be translated into its IP address. This process is known as direct DNS Resolution, i.e., converting names into IP addresses.
it is frequently also necessary to perform the reverse operation, known as Reverse Resolution.
This conversion attempts to find the name associated to an IP address.
Reverse resolution is only possible with the use of a pseudo-domain, "in.addr-arpa", an acronym for "Address and Routing Parameter Area."
DNS delegation of this pseudo-domain is responsibility of Internet Registries, as they are responsible for allocating IP addresses.
All allocated IP address space must have an associated DNS server, which shall be responsible for reverse resolution. In the case of LACNIC's area of coverage [Annex 1], these servers must be registered at LACNIC, which in turn is responsible for the reverse resolution of blocks administered by this organization.
LACNIC may use information obtained through reverse resolution as an indicator of the utilization of allocated IP address blocks.
DNS server registration of the IP address space administered by LACNIC shall vary according to the size of the allocated space.
Blocks allocated by LACNIC with prefixes shorter than or equal to /16 shall have their DNS servers responsible for reverse resolution registered at LACNIC. Information shall be entered in relation to /16 blocks. Suballocations of segments with longer prefixes within these blocks shall have their DNS servers registered at the organizations that received the blocks with prefixes shorter than or equal to /16 directly from LACNIC.
Blocks allocated by LACNIC with prefixes longer than /16 shall register at LACNIC the DNS servers responsible for the reverse resolution of all blocks with the prefix /24 that account for the total IP address space allocated by LACNIC. Thus, suballocations with prefixes of up to /24 made within these blocks must have their DNS servers registered at LACNIC.
Prefix of the block allocated by LACNIC - DNS server for suballocations made by LACNIC must be registered at: