How to find AS Number from an IP

Yesterday there was a slight problem on the office network. IP blocks for upstream B was passed from upstream A. Once the problem is finished, it’s fun to see record ASN from the internet provider company here: (7713 is the U.S. from Telkom)

I’m curios who’s Google peering with? Finally a little Googling found this link, from IP to ASN Finding ASN from IP Address, turned out quite easily.

First we search first one ip from Google. We use the command ‘host’ It would appear many ip, I Choose, then we use whois command:

whois -h -v

The result is as below

Warning: RIPE flags Used with a traditional server.
AS   |IP            | BGP Prefix     | CC   | Registry | Allocated  | U.S. Name
15169| | | U.S. | ARIN     | 2004-11-10 | GOOGLE - Google Inc..

Left column is Google’s ASN. We enter into his looking glass so it looks like:

Please see BGP peering and statistics from Google.

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  • Brad

    Can someone articulate a synopsis of what “this”, is telling me??:Warning: RIPE flags used with a traditional server.

    # ARIN WHOIS data and services are subject to the Terms of Use
    # available at:
    # If you see inaccuracies in the results, please report at

    # Query terms are too ambiguous. Please refine query.

    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 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 to
    locate domain information, and for military network information.

    Many operating systems provide a whois utility. To conduct a query from the
    command line, such as:
    whois -h hostname
    (e.g. whois -h foo)

    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.

    To limit your query to a specific record type, include one of the following
    n Network address space
    r CIDRized network space
    d Delegations
    a Autonomous systems
    p Points-of-contact
    o Organizations
    c End-user customers
    e Points-of-contact, Organizations, End-user customers
    z All of the above

    To limit your query to a specific record attribute, include one of the
    following flags:
    @ Searches for matches by domain-portion of an email
    ! Searches for matches by handle or id
    / Searches for matches by name
    . Searches for matches by name
    (same as above, but some WHOIS clients have problems with .)

    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:
    + FULL output shows detailed display for EACH match
    – LIST output shows summary only, even if single match

    The + flag cannot be used with the sub-query features described below.

    Record hierarchy:
    Records in the ARIN WHOIS database have hierarchical relationships with other
    records. To display those related records, use the following flags:

    Displays the record related down the hierarchy. For a network,
    display the subdelegations, or subnets, below the network, in
    list format. For an organization or customer, display
    the resources registered to that organization or customer, in
    list format.
    = Display only an exact match in the hierarchy.

    Wild card queries:
    WHOIS supports wild card 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
    parenthesis 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
    limit has been reached for each record type. 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 with the
    appropriate details.

    To correct information within your area of responsibility, submit a
    template to Information on how to fill out the
    appropriate template can be found at:
    To notify ARIN of invalid POC information, contact
    with the relevant information.

    Terms of Service:

    ARIN WHOIS data and services are subject to the Terms of Use
    available at:
    No match found for -r n +

    # ARIN WHOIS data and services are subject to the Terms of Use
    # available at:
    # If you see inaccuracies in the results, please report at

  • budiwijaya

    Hi Brad, looks like you’ve entered incorrect command.