ipcalc - IP Calculator. ipcalc takes an IP address and netmask and calculates the resulting broadcast, network, Cisco wildcard mask, and host range. By giving a second netmask, you can design subnets and supernets....
Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
whatmask - Whatmask is a small C program that will help you with network settings and subnet calculations.
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Dipiscan - Présentation et téléchargement de logiciels en freeware pour Windows, développés par Damien PONNELLE
Better Uptime - We call you when your website goes down