The ASN (Autonomous System Number) is a globally unique number assigned by a registrar for the purposes of Internet routing, To determine this issue the following command:

NOTE: The date and time part of the query is for the date / time you want to query.

whois -h whois.cymru.com " -v 5.42.134.35 2010-05-12 12:00:01 GMT"

returns:

AS      | IP               | BGP Prefix          | CC | Registry | Allocated  | Info                    | AS Name
8680    | 5.42.134.35      | 5.42.132.0/22       | GB | ripencc  | 2012-05-16 | 2010-05-12 12:00:01 GMT | , GB

To query for some basic AS information directly:

whois -h whois.cymru.com " -v AS8680"

returns:

AS      | CC | Registry | Allocated  | AS Name
8680    | GB | ripencc  |            | , GB

• https://asn.cymru.com/
• https://www.ultratools.com/tools/asnInfoResult?domainName=8.8.8.8