This is dhcpd-pools which is made for ISC dhcpd pool range analysis. With this command you can check usage of pool addresses when address space is great. Command is designed so that it will not get slow even there is thousands of IPs in lease file. This kind of huge dhcpd installation can be near by DSL DSLAMs or some other public access connection points. This command will not print nice to know information like DHCPStatus does. Output is limited only to list only usage for ranges, shared network and total address space. Limiting what is printed is the right thing to do when there is thousands of addresses. If your address space is small some other dhcp analyzer might be more suitable for you. Source code is pretty printed by using indent command switches. -kr -i8 If you write a patch please use same coding style. In general the style is copy from Linux kernel. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob_plain;f=Documentation/CodingStyle;hb=HEAD A dhcpd-pools home page is located at SourceForge. http://dhcpd-pools.sourceforge.net/