DNSstuff is a web application that empowers users with tools and expertise to test, resolve and configure their DNS and network.These are the tools they provide-DNS Report,DNS TIming,WHOIS Lookup,IP Tests like SPAM DatabaseLookup,ReverseDNS Lookup,IPWHOIS Lookup,IP Information,Hostname Tests like DNS Lookup,Traceroute,PING,ISP Cached DNS Lookup,Additional Tests like Abuse Lookup,Decimal IPs,E-mail Test,URL DEOBFUSCATORCIDR/Netmask,CSE HTML Validator,Free E-mail Lookup Most of them are paid tools.