Tag Archives: AS Number

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: http://bgp.he.net/AS7713 (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 http://www.team-cymru.org/Services/ip-to-asn.html Finding ASN from IP Address, turned out quite easily.

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

whois -h -v whois.cymru.com

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 HE.net so it looks like: http://bgp.he.net/AS15169

Please see BGP peering and statistics from Google.

find AS number, as number lookup, google autonomous system number, how to find AS number, find as number for ip, how to check as number, find as from ip, how to find as number for an ip address, AS from IP, as number IP