Relevant Links
Training
Querying ARIN's WHOISAn online training module to learn to structure a query in ARIN's WHOIS and how to understand the information that is retrieved.
WHOIS Servers
ARIN's WHOIS service provides a mechanism for finding contact and registration information for resources registered with ARIN. ARIN's database contains IP addresses, autonomous system [AS] numbers, organizations or customers that are associated with these resources, and related Points of Contact [POC].
ARIN's WHOIS will NOT locate any domain related information, nor any information relating to military networks. Please use whois.internic.net to locate domain information, and whois.nic.mil for military network information.
Many operating systems provide a whois utility. To conduct a query from the command line, the format is:
whois -h hostname identifier e.g. whois -h whois.arin.net
To obtain a more specific response, you may conduct a search by using certain flags. Many of these flags can be combined to tailor the desired output. Flags must be separated from each other and from the search term by a space. Your results will vary depending on the refinements you apply in your search. Listed below are the flags currently available; you may only use one flag from each flag-type in a query (i.e. one record type, one attribute, etc.).
Query-by-record-type:
To limit your query to a specific record type, include one of the following flags:
- n - Network address space
- a - Autonomous systems
- p - Points of Contact
- o - Organizations
- c - End-user customers
Query-by-attribute:
To limit your query to a specific record attribute, include one of the following flags:
- @ <domain name> - Searches for matches by the domain-portion of an e-mail address
- ! <handle> - Searches for matches by handle or id
- . <name> - Searches for matches by name
Searches that retrieve a single record will display the full record. Searches that retrieve more than one record will be displayed in list output.
Display flags:
To modify the way that the query results display, include one of the following flags:
- + Shows detailed (aka 'full' output) display for EACH match
- - Shows summary only (aka 'list' output), even if single match returned
The + flag cannot be used with the sub-query feature described below.
Record hierarchy:
Records in the ARIN WHOIS database have hierarchical relationship with other records. To display those related records, use the following flags:
- < Displays the record related up the hierarchy. For a network, display the supernet, or parent network in detailed (full) format.
- > Displays the record(s) related down the hierarchy. For a network, display the subdelegation(s), or subnets, below the network, in summary (list) format. For an organization or customer, display the resource(s) registered to that organization or customer, in summary (list) format.
Wildcard queries:
WHOIS supports wildcard queries. This feature is only supported as a trailing character option. To take advantage of this append the query with an asterisk (*). This can also be used in combination with any flags defined above.
Other helpful hints:
To guarantee matching only a single record, look it up by its handle using a handle-only search. In the record summary line, the handle is shown in parentheses after the name.
When using a handle to conduct a search for POC information, be sure to add the -ARIN extension.
Queries that return more than 256 results will stop displaying data after the 256th result. You may want to narrow your search criteria or add flags to your query to limit the results.
To search on an individual's name, you may enter the last name, or to further restrict results, use the last name and first name, separated by a comma. For example: Smith, John.
Contact us:
For operational problems with WHOIS please contact noc@arin.net with the approporiate details.
To correct information within your area of responsibility, submit a template to hostmaster@arin.net. Information on how to fill out the appropriate template can be found at: http://www.arin.net/registration/templates//template_instructions.html.
To notify ARIN of invalid POC information, contact hostmaster@arin.net with the relevant information.