1. CIDR network aggregation and filtering aggregate is a tool for aggregating CIDR networks. Input is read from stdin and output is written to stdout. It understands IPv4 networks represented as network/prefix, network/netmask and start_address - end_address. It is able to read input in any one of these formats and output in the same or a different format. It is also able to limit the maximum and minimum prefix length that will be output. This can be used to filter, for instance ignoring all networks with a prefix longer than 24 bits. That is all networks smaller than a traditional Class C. From Debian 3.0r0 APT