ISC dhcpd leases usage analysis
This is dhcpd-pools ISC dhcp shared network and pool range usage analysis. Purpose of command is to count usage ratio of each IP range and shared network pool which ISC dhcpd is in control of. Users of the command are most likely ISPs and other organizations that have large IP space. Program is written C. Design goal is to get analysis done quickly where there is lots of data. On cheap laptop the speed of analysis is roughly 100k leases per second. Number of ranges, or shared networks, does not make any significant difference in getting analysis done.
Intelligently block brute-force attacks by aggregating system logs
SSHGuard protects hosts from brute-force attacks against SSH and other services. It aggregates system logs and blocks repeat offenders using several firewall backends, including iptables, ipfw, and pf.