sipcalc

Advanced console-based ip subnet calculator
Sipcalc is an advanced console-based IP subnet calculator. It can take
multiple forms of input (IPv4/IPv6/interface/hostname) and output a
multitude of information about a given subnet.
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Features include:
- IPv4
* Retrieving of address information from interfaces.
* Classfull and CIDR output.
* Multiple address and netmask input and output formats (dotted
quad, hex, number of bits).
* Output of broadcast address, network class, Cisco wildcard, hosts/range,
network range.
* The ability to "split" a network based on a smaller netmask, now also with
recursive runs on the generated subnets. (also IPv6)
- IPv6
* Compressed and expanded input and output addresses.
* Standard IPv6 network output.
* v4 in v6 output.
* Reverse DNS address generation.