Whois FAQ

How do I run a Whois query?

There are two different ways to query the server:

  • From a computer where the Whois client software is installed, using a command line interface and the following syntax: whois –h.
  • Via the LACNIC website at: https://query.milacnic.lacnic.net/home

The information provided by the LACNIC Whois service is organized as a set of values and attributes separated by colons (“:”).

When an ASN or IP address block is queried, the answer returned includes, among others, the following attributes:

  • “owner:” Name of the organization holding the queried resource
  • “ownerid:” Handle for the organization in the LACNIC database
  • “responsable:” Name of the point of contact (person or group) at the organization
  • “address:” Postal address of the organization
  • “country:” Country code of the organization
  • “phone:” Telephone number of the organization
  • “owner-c:” Handle for the organization's point of contact
  •  “tech-c:” Handle for the IP address block’ technical point of contact
  • “routing-c:” Handle for the ASN's technical point of contact;
  • “abuse-c:” Handle for the organization's abuse contact
  • “created:” Date on which the resource was assigned
  • “changed:” Date on which the resource data was last modified

The above is followed by information about the point of contact associated with this resource. Returned attributes include:

  • “nic-hdl:” Handle for the point of contact
  • “person:” Name of the person or group representing this point of contact
  • “e-mail:” Email address for this point of contact
  • “address:” Postal address for the point of contact
  • “country:” Country code for the point of contact
  • “phone:” Telephone number for the point of contact
  • “created:” Date on which this record was created in the database
  • “changed:” Date on which this point of contact's information was last modified

When an IP address block is queried, in addition to the attributes listed above, DNS reverse delegation information may also be available, including the following attributes:

  • “inetrev:” Shows the complete or partial block that was delegated
  • “nserver:” Name of the DNS server
  • “nsstat:” Status of this DNS server
  • "ns”astaa:” Date on which an “ok” status was last obtained for this server

Even in the case of queries for IP address blocks that have been sub-assigned to other organizations, the data returned by the system will refer to the sub-assignment's parent block, i.e., the original block from which the sub-assignment was made. In this case, the “inetnum-up” attribute will be used.

In addition queryig by ASN or IP address, the LACNIC Whois system allows querying by point of contact handle. In this case, the system will only returns the point of contact's name, postal address, email address, and telephone number.

Finally, the LACNIC Whois system also allows querying by organization handles. In addition to the information about the organization mentioned above, the answer to this type of query will include a list of all the Internet resources assigned to this organization. The answer to such queries includes the following attributes:

  • “aut-num:” ASN assigned to the organization.
  • “inetnum:” IPv4 or IPv6 address block assigned to the organization.
What are the differences between Whois and Geofeeds?

LACNIC uses different means to publish information on IP assignments and sub-assignments: Whois port 43, Bulkwhois, RDAP, the delegations file, the dbase/lacnic.db.gz file created as a result of policy LAC-2018-3, among others. These provide contact information for the organizations that have been assigned IP addresses.

The geographic information (postal address, city, country) provided by LACNIC is the information provided by each member These may not match the location where the IP resources are actually being used.

Because this registry is publicly available and free to use, some organizations are using this information for IP geolocation purposes. Due to the nature of the data, this practice has low accuracy and creates issues for customers, ISPs, content providers, and others.

Geofeeds is as a free, publicly available alternative that allows operators in the region to explicitly state where their IP addresses are being used and to sub-divide the blocks they have been assigned, specifying location information for each sub-block. This information can include information such as country, region, and city. And all of this in a single tool specifically designed for this purpose.

When was the Whois system created?

The Whois system was originally described in RFC 812, which was later made obsolete by RFC 3912, Whois Protocol Specification. As described in the original document, Whois was a netwide point of contact directory service for ARPANET users. The system does not specify which format should be used in the answers to the queries the system receives. This is why different Whois systems provide information in different formats.

How do I find my organization's userID?

To see the userID of an organization's technical contact, go to https://query.milacnic.lacnic.net/home. In the search box, enter a resource assigned to your organization (IPv4 or IPv6 address block, or ASN). The owner-c field of the search results page will display the userID for your organization.

How do I find my organization's Owner-ID?

Each Internet resource assigned by LACNIC is associated with an entity that represents the organization that received the resource. All entities registered in LACNIC's system have a code, their Owner-ID.

To find the Owner-ID associated with an organization, simply query one of the Internet resources assigned to that entity in the LACNIC Whois. The response to this query will include the organization's Owner-ID. In Unix systems, you can also use the following command: whois -h whois.lacnic.net Owner-ID.

How do I find all the resources assigned to my organization?

You can query the organization's Owner-ID in the LACNIC Whois database. At the bottom of the results page you will see a list of the resources assigned to the organization under the following tags:

aut-num: for autonomous system numbers (ASN)

inetnum: for IPv4 and IPv6 address blocks

On Unix systems, you can also use the following command:

whois -h whois.lacnic.net IPv4

whois -h whois.lacnic.net IPv6

whois -h whois.lacnic.net ASN

Why do the IP addresses assigned to my company appear to have a mailing address in Uruguay?

Certain traceroute or IP lookup tools are still configured to query the Whois database of the three RIRs that existed before LACNIC was created (APNIC, ARIN and RIPE NCC).

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

Now, the ARIN Whois server reports simply that these blocks were transferred to LACNIC, whose administrative headquarters are located in Uruguay. It also suggests peforming an additional query on the LACNIC Whois. This is why certain tools that query the ARIN but not the LACNIC Whois server report the postal address of all block addresses as being in Uruguay.