Searching Whois Using a CLI

Using Command-Line Interface (CLI) Clients with Whois

You can access ARIN’s Whois information by connecting to a Whois server using CLI commands entered into a terminal window. The following sections provide instructions for accessing ARIN’s Whois using the CLI.

To use Whois from a terminal window, enter your query from the CLI. You can use different flags to restrict your search or display specific output.

Submitting a Whois Query from a Terminal

To submit a Whois query from a terminal, enter:

whois -h whois.arin.net “flag search-term”

The parts of this command are:

• whois: the command itself
• -h: specifies that the hostname of the Whois server will follow
• whois.arin.net: the name of ARIN’s Whois server
• flag: narrows the search by restricting the results to those that match criteria designated by the flag (see the following table)
• search-term: the information for which you are searching

Using Flags

You may use flags with the query to narrow down the search criteria. Depending on the terminal client, you may not have to include quotes around the flag and/or search term. If you do not include a flag, the Whois server attempts to guess what information you are looking for and parses the query.

The flags to restrict the records are listed in the following table. Flags must be separated from each other and from the search term by a space. You can only use one flag of each type in a query (for example, one record type, one attribute, or one display flag).

Query Flags

In this table, all examples assume that the user is on a Mac and entering commands within the terminal app window.

Output Flags

Searches that retrieve a single record will display the full record. Searches that retrieve more than one record will be displayed in list output. You can use the + and - flags to modify the output if a query retrieves more than one record.

Record Hierarchy Flags

Records in ARIN’s Whois have hierarchical relationships with other records. For example, a network can have parent networks and child networks. To display those related records, use the flags described as follows.

Using Wildcards

To perform a wildcard query, substitute an asterisk (*) for the alphanumeric characters that you want to leave off the end of the query term. For example, this query performs a search for POCs beginning with or equal to North, and would also return results with Northcutt, Northington, Northrup, etc.:

whois -h whois.arin.net “p north*”

Wildcards can be used with any other flags.

Interpreting Whois Results

Results for Whois queries performed using the ARIN website or the command-line interface contain information about IPv4 and IPv6 address space, ASNs, POCs, and Orgs. Depending on the query options chosen or query flags used, the fields shown in the following tables may or may not be displayed in the result. Some fields appear in results from multiple query types; these are listed in the Common Fields Found on Multiple Record Types section.

Network Information

Network records (NETs) define a range of IPv4 or IPv6 addresses and show the organizations and POCs with authority over them.

Organization Information

Organization information includes the Org ID to which resources are issued and the contact information for the Org POCs.

ASN Information

ASN records, much like NET records, display the specific ASN and the Org with authority over it.

Point of Contact

POC information provides a name, mailing address, and contact information, and lists any organizations or resources over which the POC has authority.

Delegation/Reverse DNS

Delegations are entries that relate IP addresses to domain names using the Domain Name System (DNS) of the Internet. Delegations contain the information necessary for Reverse DNS, including the associated nameservers, and DNS Delegation Signer (DS Record) information.

Common Fields Found on Multiple Record Types

These fields may display in the results of multiple types of queries.

Getting Help with Whois

• For operational problems with Whois, please log in to your ARIN Online account and create an Ask ARIN ticket, or contact the ARIN Help Desk with the appropriate details.
• To report inaccurate information in Whois, you can file a report online.