ZMap is described as 'fast single packet network scanner designed for Internet-wide network surveys. On a typical desktop computer with a gigabit Ethernet connection, ZMap is capable scanning the entire public IPv4 address space in under 45 minutes' and is an app in the Network & Admin category. There are more than 10 alternatives to ZMap for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and Android. The best alternative is Nmap, which is both free and Open Source. Other great apps like ZMap are Angry IP Scanner (Free, Open Source), Fing (Freemium), Zenmap (Free, Open Source) and Advanced IP Scanner (Free).
Angry IP scanner is a very fast IP address and port scanner. It can scan IP addresses in any range as well as any their ports. It is cross-platform and lightweight. Not requiring any installations, it can be freely copied and used anywhere.
Zenmap is the official cross-platform GUI for the Nmap Security Scanner. It is free and runs on Linux, Windows, Mac OS X, etc. Zenmap aims to make Nmap easy for beginners to use while providing advanced features for experienced Nmap users.
Reliable and free network scanner to analyse LAN. The program shows all network devices, gives you access to shared folders, provides remote control of computers (via RDP and Radmin), and can even remotely switch computers off. It is easy to use and runs as a portable edition.
Advanced Port Scanner is a fast and free software for port scanning. It will allow you to quickly find all open ports (TCP and UDP) and detect versions of programs running on them. The utility includes many features simplifying network management.
MASSCAN produces results similar to Nmap , the most famous port scanner. Internally, it operates more like scanrand, unicornscan, and ZMap, using asynchronous transmission. The major difference is that it's faster than these other scanners.
Fingbox is a cloud system to monitor and manage your network, based on Fing Apps, Applications and Tools. It's a secure, cross-platform, comprehensive solution to discover devices, scan services, analyze and customize your networks, from anywhere.
IP Scanner for Macintosh scans your local area network to determine the identity of all machines and internet devices on the LAN. Powerful results, yet easy and intuitive to use. Runs on OS X 10.4 and above.
The IPPINGER is an application for checking a host or multiple hosts periodically. It can check IPs, websites and also ports (if are open). It can be configured to notify by email or Windows Notification when a host is down.