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: (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 Finding ASN from IP Address, turned out quite easily.

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

whois -h -v

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 so it looks like:

Please see BGP peering and statistics from Google.

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