tcllib_ip(n)							Domain Name Service						      tcllib_ip(n)

__________________________________________________________________________________________________________________________________________________

NAME

       tcllib_ip - IPv4 and IPv6 address manipulation

SYNOPSIS

       package require Tcl  8.2

       package require ip  ?1.2?

       ::ip::version address

       ::ip::is class address

       ::ip::equal address address

       ::ip::normalize address

       ::ip::contract address

       ::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  effec-
	      tively 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::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 equiva-
	      lent 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 pre-
	      fixes.

		% ::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 pre-
	      fix 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 SF Trackers [http://sourceforge.net/tracker/?group_id=12883].  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>

dns									1.3							      tcllib_ip(n)