Resource Administration System and Whois Service (FAQ)

How can I reset the password I use to login to the system?

To reset your password, go to, scroll to the bottom of the screen and click on the “Forgot your password?” button. Enter your user ID in the userID field and click “Send.” The system will send a message to the e-mail address linked to the user, which you can then use to reset your password.

Check your inbox. If you can’t find the message, check your spam folder. If you still can’t find this message, please contact for assistance.

How can I check my Organization's userID?

To find out the userID of an Organization's technical contact, go to In the search box, enter a resource assigned to your Organization (IPv4 block, IPv6 block or ASN). Search results will include an owner-c field, which will show your Organization's userID.

To see the help video on this topic, click on the following link:

How can I check my organization's OWNER-ID?

All Internet resources assigned by LACNIC are associated with an Entity that represents the organization receiving the resource. All entities registered in LACNIC's s­­ystem have a unique identifier? the OWNER-ID.

To find out the OWNER-ID associated with an organization all you must do is query one of the Internet resources assigned to that entity using WHOIS LACNIC.service

The response to this query will include a field (ownerid) with the organization's OWNER-ID.

On Unix systems the following command can also be run: whois ?h OWNER-ID

How can I check all the resources assigned to my organization?

You can perform a query on WHOIS LACNIC service using the organization's OWNER-ID. The lower part of the query results shows the list of resources assigned to the organization under the following labels:

  1. aut-num: autonomous system numbers (ASN).
  2. inetnum: IPv4 and IPv6 address blocks.

On Unix systems the following commands can also be run:

  1. whois ?h IPv4
  2. whois ?h IPv6
  3. whois ?h ASN

How can I change my language preferences for LACNIC's resource management system?

The system can be used in three different languages: English, Spanish and Portuguese.

By default, the interface uses the language selected by the user at the time of registering on the system.

Existing users can modify this information. To do so, login to MiLACNIC, click on your username in the upper left corner of the screen and then click on “Profile.” In the following screen, select the language you wish to use permanently.

Otherwise, you can select a temporary language by clicking on the options shown in the upper right corner of the screen: “ES” (Spanish) “EN” (English) or “PT” (Portuguese).

Why does my computer say that the IP addresses assigned to my company have a postal address in Uruguay?

Some traceroute or IP query tools are still configured to query the WHOIS database of the three RIRs that existed before LACNIC's creation (APNIC, ARIN and RIPE NCC).

Before 29 July 2002, IP addresses in the block were administrated by ARIN. Since then, these blocks have become LACNIC's responsibility.

ARIN's Whois server now only reports that these blocks have been transferred to LACNIC, whose administrative headquarters are located in Uruguay. It also suggests performing an additional query on WHOIS de LACNIC server.

This is why certain tools that query ARIN's but not LACNIC's WHOIS server report the postal address of all block addresses as being in Uruguay.

LACNIC has reached out to some of these tools' developers to facilitate any necessary updates to their products.

How can I update the information of an IP address block or ASN that was not assigned by LACNIC?

Before updating your resource's information, it is first necessary to update the information that LACNIC received from ARIN.

To do so, you must first request an "update password" from LACNIC's Hostmaster (one-time password). Your email to the Hostmaster must include the organization's OWNER-ID as well as the point of contact's USER-ID. You will then be emailed a password that can be used to update the Entity's information.

Simply log into LACNIC's resource administration system ( with your USER-ID and personal password and then click on the "Legacy Resources" button.

Enter the organization's OWNER-ID and the password that was emailed to you on this screen.

At the end of this process, the resources assigned to this entity will be visible on the system's home page and the authenticated user, i.e. the USER ID that will be the contact for these resources, will be able to manage them.

How I can manage the resources assigned to my organization?

IP address blocks and ASNs must be managed by their technical contact. For this, you must log into LACNIC's system at Mi LACNIC with your userID and personal password.

The resources for which you are the technical contact will be shown on the system's home page. To manage your resources you must click on an IP address block or ASN.

In the case of IP address blocks, you will the option to sub-assign addresses to third parties, delegate reverse DNS resolution, verify the utilization of the blocks that have already been assigned, and register the ASN through which the block is announced.

I can log into LACNIC's system with my userID and password, but I can't see any IP address blocks or ASNs assigned to my organization. What should I do?

Check if the userID used to access the system is the technical contact for any IP address blocks or ASNs.

To do so, query the IP address block or ASN in LACNIC's WHOIS server and look for the "tech-c" field in the response. It will show the userID of the queried IP address block or ASN's technical contact. This is the userID that must be used to manage the resource or the user “owner-c”.

How can I manage my organization's points of contact?

To change or modify the points of contact of an Organization, follow the instructions below:

  1. Go to and login with the userID of your Organization's administrative contact.

Note: each LACNIC member organization has three points of contact: an administrative contact, a billing contact and a membership contact.

  1. Once you have logged in, go to the menu on the left and select the “Information” option for your organizations’ OrgID.
  2. The following screen will show an “Edit Contacts” button that will allow you to modify the administrative, billing and membership contacts. To do so, use the corresponding userID or search for the name of the person or e-mail address associated with your userID.

Detailed help on this topic is available at the following link:

How can I register a sub-assignment in LACNIC's database?

According to the LACNIC policies currently in force, any sub-assignment to a third party consisting of a /29 or smaller prefix (i.e. 8 or more IP addresses) must be registered on LACNIC's database and its data must be available via a whois query. To complete this registration, follow the instructions below:

  1. Go to and login with your Organization's userID.
  2. Once you have logged in, go to the side menu, select the “IP/ASN” option and identify the main block assigned by LACNIC on which you are going to work. Then select the “Sub-assign” option.
  3. In the following screen, you must enter the “ownerid” or “orgID” or search for the name of the organization that will receive the block. If the recipient of the sub-assignment does not have a registered orgID, you can use the option on the right to complete certain information which will automatically create an “orgID” for them.
  4. You can then select the block size and specific range you wish to assign to the recipient specified above.

Bear in mind that in order to reach prefixes longer than a /24, i.e. blocks smaller than a Class C, you must have properly delegated your reverse DNS resolution.

Detailed help on this topic is available at the following link:

What are legacy resources?

Legacy resources are those that were assigned before the creation of Regional Internet Registries (RIRs). All Internet resources (IP address blocks or ASNs) assigned prior to December 28, 1997 are regarded as legacy resources.

For more information you can access our web site

Can legacy resources be managed with LACNIC's resource management system?

All resources under LACNIC's responsibility can be managed through LACNIC's web-based system (

Some resources were transferred from ARIN to LACNIC, and these need to be updated before they can be managed with the web-based system MILACNIC.

Are there any differences between legacy and non-legacy resources?

No. Both are valid Internet resources and can be used normally by the organization to which they ere allocated/assigned. This differentiation is important because non-legacy resources have been assigned by RIRs according to policies proposed and approved by each region's community. Organizations with legacy resources are generally not members of LACNIC, unless they have also been assigned IPv6 addresses.

How can I update legacy resource information?

The purpose of updating the information on transfered resources is to help LACNIC associate the resources with a technical contact and with the administrative contact of the organization holding such resources.

To perform this update, contact and request assistance for this process. Our hostmasters will provide you with a step-by-step guide on how to you update this information.

In certain cases, in addition to this update, it may also be necessary to correct or modify the name of the organization. In this case, a resources transference should be requested.