How to trace an IP address to the correct network

Every computer on the Internet has a unique identifying number, called an IP Address. A typical IP address looks like this:

The appropriate Regional Internet Registry (RIR) delegates the IP addresses. There are four main RIR’s, to see who is assigned a given ip address and find out what the contact is you can do a whois. If the IP Address does not belong to them they will direct you to the correct network. Below are the Regional Internet Registry’s and links to their whois page:

American Registry for Internet Numbers

Asia Pacific Network Information centre

Latin-American and Caribbean IP Address Registry

RIPE NCC (Europe)

For example: if you type in on ARIN’s whois and click submit. This will give you a Tech or Abuse e-mail address you can contact with any reports. In this example you would then submit a log of the incident to

OrgName: Road Runner
Address: 13241 Woodland Park Road
City: Herndon
StateProv: VA
PostalCode: 20171
Country: US

NetRange: -
NetHandle: NET-24-160-0-0-1
Parent: NET-24-0-0-0-0
NetType: Direct Allocation
NameServer: DNS1.RR.COM
NameServer: DNS2.RR.COM
NameServer: DNS3.RR.COM
NameServer: DNS4.RR.COM
RegDate: 2000-06-09
Updated: 2002-08-22

TechHandle: ZS30-ARIN
TechName: ServiceCo LLC
TechPhone: +1-703-345-3416

OrgAbuseHandle: ABUSE10-ARIN
OrgAbuseName: Abuse
OrgAbusePhone: +1-703-345-3416

OrgTechHandle: IPTEC-ARIN
OrgTechName: IP Tech
OrgTechPhone: +1-703-345-3416