Webfwlog is a Web-based firewall log reporting and analysis tool. It allows users to design reports to use on logged firewall data in whatever configuration they desire. Included are sample reports as a starting point. Reports can be sorted with a single click, or "drilled-down" all the way to the packet level, and saved for later use. Supported log formats are netfilter, ipfilter, ipfw, ipchains, and Windows XP. Netfilter support includes ulogd MySQL or PostgreSQL database logs using the iptables ULOG target.
grepcidr can be used to filter a list of IP addresses against one or more Classless Inter-Domain Routing (CIDR) specifications, or arbitrary networks specified by an address range. As with grep, there are options to invert matching and load patterns from a file. grepcidr is capable of comparing thousands or even millions of IPs to networks with little memory usage and in reasonable computation time. It has endless uses in network software, including mail filtering and processing, network security, log analysis, and many custom applications.