9.10. Network Address Type Functions

Table 9-31 shows the operators available for the cidr and inet types. The operators <<, <<=, >>, and >>= test for subnet inclusion. They consider only the network parts of the two addresses, ignoring any host part, and determine whether one network part is identical to or a subnet of the other.

Table 9-31. cidr and inet Operators

< is less thaninet '' < inet ''
<= is less than or equalinet '' <= inet ''
= equalsinet '' = inet ''
>= is greater or equalinet '' >= inet ''
> is greater thaninet '' > inet ''
<> is not equalinet '' <> inet ''
<< is contained withininet '' << inet '192.168.1/24'
<<= is contained within or equalsinet '192.168.1/24' <<= inet '192.168.1/24'
>> containsinet'192.168.1/24' >> inet ''
>>= contains or equalsinet '192.168.1/24' >>= inet '192.168.1/24'

Table 9-32 shows the functions available for use with the cidr and inet types. The host, text, and abbrev functions are primarily intended to offer alternative display formats. You can cast a text value to inet using normal casting syntax: inet(expression) or colname::inet.

Table 9-32. cidr and inet Functions

FunctionReturn TypeDescriptionExampleResult
broadcast(inet)inetbroadcast address for networkbroadcast('')
host(inet)textextract IP address as texthost('')
masklen(inet)integerextract netmask lengthmasklen('')24
set_masklen(inet, integer)inetset netmask length for inet valueset_masklen('', 16)
netmask(inet)inetconstruct netmask for networknetmask('')
hostmask(inet)inetconstruct host mask for networkhostmask('')
network(inet)cidrextract network part of addressnetwork('')
text(inet)textextract IP address and netmask length as texttext(inet '')
abbrev(inet)textabbreviated display format as textabbrev(cidr '')10.1/16

Table 9-33 shows the functions available for use with the macaddr type. The function trunc(macaddr) returns a MAC address with the last 3 bytes set to zero. This can be used to associate the remaining prefix with a manufacturer. The directory contrib/mac in the source distribution contains some utilities to create and maintain such an association table.

Table 9-33. macaddr Functions

FunctionReturn TypeDescriptionExampleResult
trunc(macaddr)macaddrset last 3 bytes to zerotrunc(macaddr '12:34:56:78:90:ab')12:34:56:00:00:00

The macaddr type also supports the standard relational operators (>, <=, etc.) for lexicographical ordering.