DNS delegation for IP address blocks allows reverse resolution, i.e. finding out the name associated with an IP address that is being used by a computer.
In addition to managing Internet numbering resources for Latin America and the Caribbean, LACNIC is also responsible for global reverse resolution.
To delegate the block's reverse resolution, go to www.lacnic.net, scroll to the bottom of the screen and click on My Services. Then click on the "Resource Administration System" button.
In the following screen, login using the userID of your Organization's administrative contact.
Once you've logged in, find and click on the IPv4 or IPv6 block you wish to delegate.
If you would like to delegate the entire block, in this case 201.219.252/22, click on "Deleg." In the following screen, enter the servers responsible for this block's reverse DNS resolution. Bear in mind that each Class C that makes up this /22, in this case the four /24s, must be properly configured in your server.
If you would like to delegate a smaller block, such as, for example, the first /24 corresponding to this /22, click on "Extend" and extend it to 201.219.252/24. Then click on "Deleg." In the following screen, enter your primary and/or alternate servers.
To modify existing DNS server names, click on the "AltDel" button and change the name of the servers.
Bear in mind that you must enter the servers' host names, not their IP addresses.
To see the help video on this topic, click on the following link: http://youtu.be/VgeRRUEebgA
A "Lame Delegation" means that a DNS delegation has problems. This happens when the information on the IP address block in the DNS server registered in the database is not accurate, or when the DNS server can't be accessed by LACNIC's monitoring system and, therefore, causes reverse resolution errors. You should check your DNS server configuration.
LACNIC's WHOIS server reports the status of the IP address blocks' DNS delegation and which servers are configured to respond to that assignment.
This information is available in the "nserver", "nsstat" and "nslastaa" fields of the responses provided by the WHOIS server when querying by IP address block.
The "nserver" field specifies which DNS server must respond to the delegation, the "nsstat" field specifies the delegation's status, and the "nslastaa" field specifies the date on which a correct configuration was observed on this server. To verify that your server is responding with the right information you can perform a test using the "dig" application. You should receive a "NOERROR" response. "NXDOMAIN" or "SERVFAIL" responses mean that there is a configuration error in your DNS server.
dig soa @nserver delegacion.in-addr.arpa
dig soa @NS.LACNIC.NET 80.7.200.in-addr.arpa
This can occur when the DNS servers specified in the system are not yet properly configured for the reverse resolution of an IP address block.
The DNS server must have information on every network that makes up the IP address block. For example, in the case of a /20, the server must have information on the 16 /24 networks it comprises. To check your DNS, follow the recommendations specified in the previous question.