Reverse DNS Lookup
This tool will provide you the hostname (ie www.yahoo.com) of the IP address that you enter below.
Results:
Lookup on IPv4 Address: 147.83.2.135
Hostname: upc.cat
Hostname: upc.edu
Hostname: www.upc.es
Hostname: masters.upc.edu
Hostname: edicioweb.produccio.upc.edu
Hostname: saladepremsa.upc.edu
Hostname: barcelonatech.upc.edu
Hostname: barcelonatech-upc.eu