T1 Shopper Port Scan Tool
    ARIN Whois Database Access Information such as WhoIs, location, DNS, registrar, hosting, etc. - tools for system administrators, computer scientists and engineers. Bulk IP lookup (and other tools)
    InterNIC Legacy WhoIs, registrar, name server lookups
    MX Toolbox - Super Tool (Useful for troubleshooting DNS, E-mail stuff, etc)
    Email Hippo - Check email address (Useful for troubleshooting DNS, E-mail stuff, etc)
    What's My DNS Track changes to global DNS
    Subnet-Calculator CIDR
    VirusTotal virus scanning tool
    Down for Everyone, or Just Me? Website up/down tester
    File Transfer Speed Calculator (Tech of the Internets)
    SpeedTest by OOKLA
    SpeedTest by SpeakEasy
    Check certificate chain
    Audit certificate
    Check Certificate Signing Request
    CheckTLS Test TLS connections to mailservers
    FTPTest Test FTP Server Settings
    Just Ping Ping from selected geographic location
    Glasnost (See what your ISP is doing to your connection)
    Down Detector Find outages
    Shodan The Search Engine for Computers (Security, Buildings, The Web, Webcams, IoT, HVAC, Refrigorators, Powerplants, etc... )
    File Transfer Time Calculator calculates download or copy time over a network
    FaxToy Send a fax to the number on thise site to test your fax machines
    FaxZERO Send free faxes for testing purposes
    ALL SysInternals tools!(Works in I.E. or Windows Explorer)
    HoneyProject Cyber Attack Map | I.T. Security Research Group - RWTH Aachen University
    IP Viking Cyber Attack Map | N.O.R.S.E.