Network Diagnostic

My Favorite Network Testing and Diagnostic Tools:

Online Tools URL Description
IPv4 Subnet Calculator IPv4 address and netmask and calculator
IPv6 Subnet Calculator Powerful free online IPv4/IPv6 subnet calculator, hierarchical addressing planner and IP address converter
Test IPv6 Test your browser and connection for IPv6 readiness
BGP Route Servers Most updated BGP Route Servers List in Internet
HE BGP Toolkit Hurricane Electric BGP Toolkit
HE Looking Glass Hurricane Electric’s Network Looking Glass.
Urih Free online network tools & utilities (smart whois,hash & CRC,benchmarker,reverse IP,subnet calc, etc)
Tcpdump 101 Build packet capture syntax for a variety of network devices
MXToolBox Free Blacklist, DNS and Email tools
Central Ops Free online network tools (ping, traceroute,nslookup) based on Dallas,Texas.,USA. Can use for free for 50 times per day
IP Geo Location Free IP Geolocation API and Accurate IP Lookup Database (including latitude & longitude)
DSL Reports Speed tests, ping tests and bandwidth tools
PeeringDB Freely available, user-maintained, database of networks, and the go-to location for interconnection data.
Down Detector Real-time problem & outage monitoring
WebPage Test Web page Performance Testing Tool