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 user ID field and click Send. The system will send a message to your email address and you can follow the instructions to reset your password.

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

How can I check my organization's user ID?

To find out the user ID 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). The search results will include an owner-c field, which will show your organization's user ID.

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 you must query one of the Internet resources assigned to that entity using the LACNIC Whois service. The response to this query will include a field (owner ID) 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 LACNIC Whois 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:

aut-num: Autonomous System Numbers (ASN).
inetnum: IPv4 and IPv6 address blocks.

On Unix systems the following commands can also be run:
whois ?h IPv4
whois ?h IPv6
whois ?h ASN

How can I change my language preferences for LACNIC's Resource Management System?

The system can be accessed using 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 hand corner of the screen and then click on Profile. On the following screen select the language you wish to use permanently.

Alternatively, you can select a temporary language by clicking on the options shown in the upper right hand 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 Regional Internet Registries (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; our administrative headquarters are in Uruguay. The ARIN Whois server will also suggest performing an additional query on the LACNIC Whois server. This is why a tool that queries ARIN's Whois server, but not LACNIC's, would report the postal address of all block addresses as being in Uruguay. LACNIC has reached out to some developers of these tools 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 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 (this is a 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. The resources assigned to this entity will be visible on the system's home page. The authenticated user, the holder of the user ID who is the contact for the 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 user ID 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 a specific IP address block or ASN.

In the case of IP address blocks you have the option of sub-assigning addresses to third parties, delegating reverse DNS resolution, verifying the utilization of the blocks that have already been assigned, or registering the ASN through which the block is announced.

I can log into LACNIC's system with my user ID and password, but I cannot see any IP address blocks or ASNs assigned to my organization. What should I do?
Check that the user ID applied to access the system is the technical contact for any IP address blocks or ASNs. Query the IP address block or ASN in LACNIC's Whois server and look for the tech-c field in the response. It will indicate the user ID of the queried IP address block or ASN's technical contact. This is the user ID that must be utilized 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 for your organization, follow the instructions below:

Go to and login with the user ID 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.

Once you have logged in, go to the menu on the left and select the Information option for your organization’s OrgID.

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 user ID or search for the name of the person or email address associated with your user ID. 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 (8 or more IP addresses) must be registered on LACNIC's database and its data must be available via a Whois search. To complete this registration, follow the instructions below:

Go to and login with your organization's user ID.

Once you have logged in go to the side menu, select the IP/ASN option and identify the main block assigned by LACNIC that you intend to register. Then select the Sub-assign option.

In the following screen, you must enter the owner ID 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 the required information, which will automatically create an OrgID for them.

You can then select the block size and specific range you wish to assign to the recipient specified above.

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

Further 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 28 December 1997 are regarded as legacy resources.

For more information access our web site at

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

All resources under LACNIC's purview can be managed through LACNIC's web-based system ( Those resources that were transferred from ARIN to LACNIC will 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 have been allocated. 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 transferred 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 to complete the process. Our hostmasters will provide you with a step-by-step guide on how to update this information.

In certain cases, in addition to this update on transferred resources, it may also be necessary to correct or modify the name of the organization. To do this request a resource transfer.