Robtex Domain/IP Lookup
Get detailed information about an Internet host. Enter an IP address (64.233.167.99), domain name (google.com), hostname (py-in-f99.google.com), or AS-number (AS15169) to get detailed dns information including reverse dns and forwards, whois information, who hosts the machine, and if it's listed in any RBLs (black lists).
ARIN WHOIS
DuckDuckGo
Wolfram
IP Addr Convert
RIPE WHOIS