ulog-acctd is a userspace network accounting daemon which generates log files of network traffic for accounting purposes. It collects headers of IP packets that travel through the Linux 2.4+ netfilter. It writes accounting information to a log which can include protocol type, source and destination address, port numbers, byte and packet count, and incoming and outgoing interfaces. It is easily possible to generate CISCO "IP accounting output-packets" style logs with this tool.
