ipcalc

Description

This module provides puppet parser functions for performing IP address calculations in manifests.

Setup

To use this module, install it on your module path. No further setup is necessary to use any of its features.

Conventions

The functions in this module generally operate on strings that are constructed from an IP address and either a subnet mask or a prefix length. Throughout the documentation, strings in this format are refered to as an IP/CIDR. The suffix supplies information about the address's subnet context. The following are equivalent:

• 198.51.100.5/24
• 198.51.100.5/255.255.255.0

Usage

These are the functions available in this module:

ip_address($cidr)

ip_address takes an IP/CIDR and returns just the IP address.

ip_prefixlength($cidr)

ip_prefixlength takes an IP/CIDR and returns just the prefix length.

ip_netmask($cidr)

ip_netmask takes an IP/CIDR and returns the netmask which corresponds to its prefix length.

ip_network($cidr, $offset)

ip_network takes two arguments. The first is an IP/CIDR which is required. The second is an optional numerical offset which defaults to 0. The function returns an IP/CIDR by computing the network address of the subnet containing the supplied IP/CIDR and incrementing it by the offset. Given no offset, the function returns the network address for the subnet containing the supplied IP/CIDR. The maximum reasonable value for offset is one less than the size of the subnet containing the supplied IP/CIDR but the function will probably accept larger values.

ip_broadcast($cidr, $offset)

ip_broadcast takes two arguments. The first is an IP/CIDR which is required. The second is an optional numerical offset which defaults to 0. The function returns an IP/CIDR by computing the broadcast address of the subnet containing the supplied IP/CIDR and decrementing it by the offset. Given no offset, the function returns the broadcast address for the subnet containing the supplied IP/CIDR. The maximum reasonable value for offset is one less than the size of the subnet containing the supplied IP/CIDR but the function will probably accept large values.

ip_increment($cidr, $offset)

ip_increment takes two arguments. The first is an IP/CIDR which is required. The second is an optional numerical increment which defaults to 1. The function returns an IP/CIDR with the distance of $offset from the given IP/CIDR.

Example: ip_increment('10.0.0.254/23',2) will return '10.0.1.0/23'

ip_network_size($cidr)

ip_network_size takes an IP/CIDR and returns the number of IP addresses (including network and broadcast addresses) in the IP/CIDR's subnet.

ip_offset($cidr)

ip_offset takes an IP/CIDR and returns its numerical offset. The offset is the IP/CIDR's numerical distance from the beginning of its subnet at the network address.

ip_split($cidr)

ip_split takes an IP/CIDR and return an array containing the IP/CIDRs of the top and bottom halves.

ip_subnet($cidr, $subnet_prefixlength, $index)

ip_subnet returns a subnet of the given IP/CIDR. The subnet will have subnet_prefixlength as its prefix length, and will be the $indexth such subnet in the given IP/CIDR

ip_supernet($cidr, $supernet_prefixlength)

ip_supernet returns the IP/CIDR of size $supernet_prefixlength which contains $cidr