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Author: Angry IP Scanner was developed on SourceForge.net.

What it is: Angry IP Scanner is a very fast IP scanner and port scanner. It can scan IP addresses in any range as well as any range of ports at each address.

How it works: Angry IP Scanner simply pings each IP address to check whether it's alive, then optionally resolves the hostname, determines the MAC address, scans ports, etc. Plug-ins are available that can gather additional specific information from each host. Plug-ins include FTP Detect, Windows Shares, MAC address via ARP, DNS Aliases, and others. Anyone who is able to write code can develop new plug-ins to extend the functionality of Angry IP Scanner.

Why Prasanna thinks it's cool: Our network consists of resources such as Wireless Access Points, routers, network printers, IP phones, PDAs, and of course PCs. A part of the network has static IP addresses, while other parts have dynamically assigned IP addresses. Using Angry IP Scanner I can quickly and reliably scan the network for devices online, IP addresses assigned to these network devices, open ports, and the host names and usernames on PCs.

How Prasanna uses Angry IP Scanner: Our network consists of resources such as Wireless Access Points, routers, network printers, IP phones, PDAs, and of course PCs. A part of the network has static IP addresses, while other parts have dynamically assigned IP addresses. Using Angry IP Scanner I can quickly and reliably scan the network for devices online, IP addresses assigned to these network devices, open ports, and the host names and usernames on PCs.

I have installed additional plug-ins so that I can extract NetBIOS information such as computer name, currently logged-in user, network shares, and MAC addresses. A scan is initiated by entering the IP address range. It takes a few seconds to complete the scan, and once done all the results are displayed graphically, which makes it easier to analyze.

I also use it to check if there are any rogue entries in the network by comparing it with a previously saved list, and it helps me determine if any systems are running unwanted services such as FTP, by using the plug-in FTP Detect. The tool is very flexible, with options to customize the port range, time delays, number of threads, ping count, ARP MAC for determining MAC addresses independent of NETBIOS information, and favorite IP range. It can be used as a command-line utility or in a batch file. Results can be exported to a text, CSV, HTML, XML, or IP-port list file for reference at a later date.

Recently, one of the security processes in our office required the MAC addresses of all network-enabled devices. All that I did was run the Angry IP Scanner to the gather the required information without having to ask each user.

Angry IP Scanner is one of the tools that will simplify the life of an IT Engineer.

Caveats: The scan is slightly slowed down if lot of plug-ins are loaded. And of course, a tool that gathers this kind of information can also be used by hackers or others wishing to penetrate security, so you have to be careful about who has the ability to run it.

NetApp Caveat: Angry IP Scanner is, as its name suggests, a very fast scanning tool that may overload WAN circuits, NAT tables, and firewalls. While it may be ok on a LAN, it can quickly overload slower speed links and use up firewall resources creating a Denial-of-Service situation. Anyone using this tool should have a thorough understanding of these limitations beforehand.

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