Man page of NETMASK
Section: Debian Linux (1)
Updated: 15 May 1999
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netmask - a netmask generation and conversion program
[ options ] spec [ spec ... ]
This program accepts and produces a variety of common network
address and netmask formats. Not only can it convert address and
netmask notations, but it will optimize the masks to generate the
smallest list of rules. This is very handy if you've ever configured a
firewall or router and some nasty network administrator before you
decided that base 10 numbers were good places to start and end groups
- -h, --help
Print a summary of the options
- -v, --version
Print the version number
- -d, --debug
Print status/progress information
- -s, --standard
Output address/netmask pairs
- -c, --cidr
Output CIDR format address lists
- -i, --cisco
Output Cisco style address lists
- -r, --range
Output ip address ranges
- -x, --hex
Output address/netmask pairs in hex
- -o, --octal
Output address/netmask pairs in octal
- -b, --binary
Output address/netmask pairs in binary
- -n, --nodns
Disable DNS lookups for addresses
A spec is an address specification, it can look like:
All addresses from address1 to address2.
All addresses from address1 to address1+address2.
A group starting at address spanning mask.
An address is an internet network address, it can look like:
An internet hostname.
A standard dotted quad internet address notation.
A decimal number (100 in this case).
An octal number preceded by "0" (64 in this case).
A hexadecimal number preceded by "0x" (256 in this case).
A mask is a network mask, it can look like:
A dotted quad netmask (netmask will complain if it is not a
A Cisco style inverse netmask (with the same checks).
The number of bits set to one from the left (CIDR notation).
The number of bits set to one from the left in octal.
The number of bits set to one from the left in hexadecimal.
netmask was written by Robert Stone. Some algorithm design and
optimization was provided by Tom Lear. This manual page
was written by Robert Stone.
Let me know if you find any. This man page is a bit more simplistic
than I'd like, but I've forgotten most of the groff I once knew.
- SEE ALSO
This document was created by
using the manual pages.
Time: 07:34:21 GMT, September 13, 2011