Fellow networkers,   Team Cymru is happy to announce the availability of a public whois server dedicated to mapping IP numbers to ASNs, located at whois.cymru.com.  You can find the link to this tool at:   http://www.cymru.com/BGP/whois.html   This link has been added to our main BGP data page available at:   http://www.cymru.com/BGP/index.html   We have also extended the functionality of this daemon to support BULK IP submissions for those who wish to further optimize their queries with netcat.   Following is a quick overview of how to use it:   $ whois -h whois.cymru.com <IP>   Where <IP> is replaced by the IP you'd like to map, like so:   $ whois -h whois.cymru.com 4.2.2.1     ASN |               IP | Name    3356 |          4.2.2.1 | LEVEL3 Level 3 Communications   You can also include port information, and/or timestamps in your queries.  Be sure to include quotes around your queries, or the daemon will interpret your request as multiple lines:   $ whois -h whois.cymru.com "4.2.2.1 -0600 GMT"     ASN |               IP |            Info | Name    3356 |          4.2.2.1 |       -0600 GMT | LEVEL3 Level 3 Communications   For instructions on how to submit BULK queries via netcat, simply issue the following command:   $ whois -h whois.cymru.com help   We hope you find this tool useful.  Stay tuned for more features!    If you have any comments or suggestions as to how we might improve this service, feel free to let us know!   Thanks, Steve, for Team Cymru http://www.cymru.com -- Stephen Gill