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.


References

http://networktools.nl/asinfo/