1.4 KiB
1.4 KiB
| layout | page_title | sidebar_current | description |
|---|---|---|---|
| functions | cidrsubnet function | docs-funcs-ipnet-cidrsubnet | The cidrsubnet function calculates a subnet address within a given IP network address prefix. |
cidrsubnet Function
cidrsubnet calculates a subnet address within given IP network address prefix.
cidrsubnet(prefix, newbits, netnum)
prefix must be given in CIDR notation, as defined in
RFC 4632 section 3.1.
newbits is the number of additional bits with which to extend the prefix.
For example, if given a prefix ending in /16 and a newbits value of
4, the resulting subnet address will have length /20.
netnum is a whole number that can be represented as a binary integer with
no more than newbits binary digits, which will be used to populate the
additional bits added to the prefix.
This function accepts both IPv6 and IPv4 prefixes, and the result always uses the same addressing scheme as the given prefix.
Examples
> cidrsubnet("172.16.0.0/12", 4, 2)
172.18.0.0/16
> cidrsubnet("10.1.2.0/24", 4, 15)
10.1.2.240/28
> cidrsubnet("fd00:fd12:3456:7890::/56", 16, 162)
fd00:fd12:3456:7800:a200::/72
Related Functions
cidrhostcalculates the IP address for a single host within a given network address prefix.cidrnetmaskconverts an IPv4 network prefix in CIDR notation into netmask notation.