Networking - ASN (Autonomous System Number) - Find a specific ASN
There are many search tools online such as https://www.ultratools.com/tools/asnInfo.
For example, searching for Google returns a number of ASNs.
NOTE: This returns a number of ANS associated with Google.
Alternatively:
dig google.com
returns:
; <<>> DiG 9.16.1-Ubuntu <<>> google.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2531 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65494 ;; QUESTION SECTION: ;google.com. IN A ;; ANSWER SECTION: google.com. 300 IN A 216.58.198.206 ;; Query time: 24 msec ;; SERVER: 127.0.0.53#53(127.0.0.53) ;; WHEN: Mon Jan 04 15:55:10 GMT 2021 ;; MSG SIZE rcvd: 55
NOTE: This returns the IP Address 216.58.198.206.
…then…
whois -h whois.cymru.com " -v 216.58.198.206" AS | IP | BGP Prefix | CC | Registry | Allocated | AS Name 15169 | 216.58.198.206 | 216.58.198.0/24 | US | arin | 2012-01-27 | GOOGLE, US
NOTE: This shows that that Google IP is part of ASN 15169.