Provided by: tcllib_1.17-dfsg-1_all 
NAME
tcllib_ip - IPv4 and IPv6 address manipulation
SYNOPSIS
package require Tcl 8.2
package require ip ?1.3?
::ip::version address
::ip::is class address
::ip::equal address address
::ip::normalize address
::ip::contract address
::ip::distance ipaddr1 ipaddr2
::ip::nextIp ipaddr ?offset?
::ip::prefix address
::ip::type address
::ip::mask address
::ip::prefixToNative prefix
::ip::nativeToPrefix nativeList|native ?-ipv4?
::ip::intToString number ?-ipv4?
::ip::toInteger ipaddr
::ip::toHex ipaddr
::ip::maskToInt ipmask
::ip::broadcastAddress prefix ?-ipv4?
::ip::maskToLength dottedMask|integerMask|hexMask ?-ipv4?
::ip::lengthToMask maskLength ?-ipv4?
::ip::nextNet ipaddr ipmask ?count? ?-ipv4?
::ip::isOverlap prefix prefix...
::ip::isOverlapNative ?-all? ?-inline? ?-ipv4? hexipaddr hexipmask hexiplist
::ip::ipToLayer2Multicast ipaddr
::ip::ipHostFromPrefix prefix ?-exclude prefixExcludeList?
::ip::reduceToAggregates prefixlist
::ip::longestPrefixMatch ipaddr prefixlist ?-ipv4?
::ip::collapse prefixlist
::ip::subtract prefixlist
_________________________________________________________________________________________________
DESCRIPTION
This package provides a set of commands to help in parsing, displaying and comparing
internet addresses. The package can handle both IPv4 (1) and IPv6 (2) address types.
COMMANDS
::ip::version address
Returns the protocol version of the address (4 or 6) or 0 if the address is neither
IPv4 or IPv6.
::ip::is class address
Returns true if the address is a member of the given protocol class. The class
parameter may be either ipv4 or ipv6 This is effectively a boolean equivalent of
the version command. The class argument may be shortened to 4 or 6.
::ip::equal address address
Compare two address specifications for equivalence. The arguments are normalized
and the address prefix determined (if a mask is supplied). The normalized addresses
are then compared bit-by-bit and the procedure returns true if they match.
::ip::normalize address
Convert an IPv4 or IPv6 address into a fully expanded version. There are various
shorthand ways to write internet addresses, missing out redundant parts or digts..
This procedure is the opposite of contract.
::ip::contract address
Convert a normalized internet address into a more compact form suitable for
displaying to users.
::ip::distance ipaddr1 ipaddr2
This command computes the (integer) distance from IPv4 address ipaddr1 to IPv4
address ipaddr2, i.e. "ipaddr2 - ipaddr1"
% ::ip::distance 1.1.1.1 1.1.1.5
4
::ip::nextIp ipaddr ?offset?
This command adds the integer offset to the IPv4 address ipaddr and returns the new
IPv4 address.
% ::ip::distance 1.1.1.1 4
1.1.1.5
::ip::prefix address
Returns the address prefix generated by masking the address part with the mask if
provided. If there is no mask then it is equivalent to calling normalize
::ip::type address
::ip::mask address
If the address supplied includes a mask then this is returned otherwise returns an
empty string.
::ip::prefixToNative prefix
This command converts the string prefix from dotted form (<ipaddr>/<mask> format)
to native (hex) form. Returns a list containing two elements, ipaddress and mask,
in this order, in hexadecimal notation.
% ip::prefixToNative 1.1.1.0/24
0x01010100 0xffffff00
::ip::nativeToPrefix nativeList|native ?-ipv4?
This command converts from native (hex) form to dotted form. It is the complement
of ::ip::prefixToNative.
list nativeList (in)
List of several ip addresses in native form. The native form is a list as
returned by ::ip::prefixToNative.
list native (in)
A list as returned by ::ip::prefixToNative.
The command returns a list of addresses in dotted form if it was called with a list of
addresses. Otherwise a single address in dotted form is returned.
% ip::nativeToPrefix {0x01010100 0xffffff00} -ipv4
1.1.1.0/24
::ip::intToString number ?-ipv4?
This command converts from an ip address specified as integer number to dotted
form.
ip::intToString 4294967295
255.255.255.255
::ip::toInteger ipaddr
This command converts a dotted form ip into an integer number.
% ::ip::toInteger 1.1.1.0
16843008
::ip::toHex ipaddr
This command converts dotted form ip into a hexadecimal number.
% ::ip::toHex 1.1.1.0
0x01010100
::ip::maskToInt ipmask
This command convert an ipmask in either dotted (255.255.255.0) form or mask length
form (24) into an integer number.
::ip::maskToInt 24
4294967040
::ip::broadcastAddress prefix ?-ipv4?
This commands returns a broadcast address in dotted form for the given route
prefix, either in the form "addr/mask", or in native form. The result is in dotted
form.
::ip::broadcastAddress 1.1.1.0/24
1.1.1.255
::ip::broadcastAddress {0x01010100 0xffffff00}
0x010101ff
::ip::maskToLength dottedMask|integerMask|hexMask ?-ipv4?
This command converts the dotted or integer form of an ipmask to the mask length
form.
::ip::maskToLength 0xffffff00 -ipv4
24
% ::ip::maskToLength 255.255.255.0
24
::ip::lengthToMask maskLength ?-ipv4?
This command converts an ipmask in mask length form to its dotted form.
::ip::lengthToMask 24
255.255.255.0
::ip::nextNet ipaddr ipmask ?count? ?-ipv4?
This command returns an ipaddress in the same position in the count next network.
The default value for count is 1.
The address can be specified as either integer number or in dotted form. The mask
can be specified as either integer number, dotted form, or mask length form.
The result is in hex form.
::ip::isOverlap prefix prefix...
This command checks if the given ip prefixes overlap. All arguments are in dotted
"addr/mask" form. All arguments after the first prefix are compared against the
first prefix. The result is a boolean value. It is true if an overlap was found for
any of the prefixes.
% ::ip::isOverlap 1.1.1.0/24 2.1.0.1/32
0
::ip::isOverlap 1.1.1.0/24 2.1.0.1/32 1.1.1.1/32
1
::ip::isOverlapNative ?-all? ?-inline? ?-ipv4? hexipaddr hexipmask hexiplist
This command is similar to ::ip::isOverlap, however the arguments are in the native
form, and the form of the result is under greater control of the caller. If the
option -all is specified it checks all addresses for overlap, not only until the
first one is found. If the option -inline is specified the command returns the
overlapping prefix instead of index values.
The result of the command is, depending on the specified options,
no options
The index of the first overlap found, or 0 if there is none.
-all A list containing the indices of all overlaps found, or an empty list if
there are none.
-inline
The first overlapping prefix, or an empoty string if there is none.
-all -inline
A list containing the prefixes of all overlaps found, or an empty list if
there are none.
% ::ip::isOverlapNative 0x01010100 0xffffff00 {{0x02010001 0xffffffff}}
0
% ::ip::isOverlapNative 0x01010100 0xffffff00 {{0x02010001 0xffffffff} {0x01010101 0xffffffff}}
2
::ip::ipToLayer2Multicast ipaddr
This command an converts ipv4 address in dotted form into a layer 2 multicast
address, also in dotted form.
% ::ip::ipToLayer2Multicast 224.0.0.2
01.00.5e.00.00.02
::ip::ipHostFromPrefix prefix ?-exclude prefixExcludeList?
This command returns a host address from a prefix in the form "ipaddr/masklen",
also making sure that the result is not an address found in the prefixExcludeList.
The result is an ip address in dotted form.
%::ip::ipHostFromPrefix 1.1.1.5/24
1.1.1.1
%::ip::ipHostFromPrefix 1.1.1.1/32
1.1.1.1
::ip::reduceToAggregates prefixlist
This command finds nets that overlap and filters out the more specific nets. The
prefixes are in either addr/mask form or in native format. The result is a list
containing the non-overlapping ip prefixes from the input.
% ::ip::reduceToAggregates {1.1.1.0/24 1.1.0.0/8 2.1.1.0/24 1.1.1.1/32 }
1.0.0.0/8 2.1.1.0/24
::ip::longestPrefixMatch ipaddr prefixlist ?-ipv4?
This command finds longest prefix match from set of prefixes, given a specific host
address. The prefixes in the list are in either native or dotted form, whereas the
host address is in either ipprefix format, dotted form, or integer form. The
result is the prefix which is the most specific match to the host address.
% ::ip::longestPrefixMatch 1.1.1.1 {1.1.1.0/24 1.0.0.0/8 2.1.1.0/24 1.1.1.0/28 }
1.1.1.0/28
::ip::collapse prefixlist
This commands takes a list of prefixes and returns a list prefixes with the largest
possible subnet masks covering the input, in this manner collapsing adjacent
prefixes into larger ranges.
This is different from ::ip::reduceToAggregates in that the latter only removes
specific nets from a list when they are covered by other elements of the input
whereas this command actively merges nets into larger ranges when they are adjacent
to each other.
% ::ip::collapse {1.2.2.0/24 1.2.3.0/24}
1.2.2.0/23
::ip::subtract prefixlist
This command takes a list of prefixes, some of which are prefixed by a dash. These
latter negative prefixes are used to punch holes into the ranges described by the
other, positive, prefixes. I.e. the negative prefixes are subtracted frrom the
positive ones, resulting in a larger list of describes describing the covered
ranges only as positives.
EXAMPLES
% ip::version ::1
6
% ip::version 127.0.0.1
4
% ip::normalize 127/8
127.0.0.0/8
% ip::contract 192.168.0.0
192.168
%
% ip::normalize fec0::1
fec0:0000:0000:0000:0000:0000:0000:0001
% ip::contract fec0:0000:0000:0000:0000:0000:0000:0001
fec0::1
% ip::equal 192.168.0.4/16 192.168.0.0/16
1
% ip::equal fec0::1/10 fec0::fe01/10
1
REFERENCES
[1] Postel, J. "Internet Protocol." RFC 791, September 1981,
(http://www.ietf.org/rfc/rfc791.txt)
[2] Hinden, R. and Deering, S., "Internet Protocol Version 6 (IPv6) Addressing
Architecture", RFC 3513, April 2003 (http://www.ietf.org/rfc/rfc3513.txt)
AUTHORS
Pat Thoyts
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain bugs and other
problems. Please report such in the category dns of the Tcllib Trackers
[http://core.tcl.tk/tcllib/reportlist]. Please also report any ideas for enhancements you
may have for either package and/or documentation.
SEE ALSO
inet(3), ip(7), ipv6(7)
KEYWORDS
internet address, ip, ipv4, ipv6, rfc 3513
CATEGORY
Networking
COPYRIGHT
Copyright (c) 2004, Pat Thoyts
Copyright (c) 2005 Aamer Akhter <aakhter@cisco.com>