IP

The IP type represents both IPv4 and IPv6 addresses. These are individual addresses, with no netmask. Literals may be given in a variety of formats using the usual dotted quad for IPv4 and colon-separated IPv6.

For example:

declare local var.ip IP;
set var.ip = "192.0.2.0";
set var.ip = "2001:db8::1";
set var.ip = "2002:c000:0204::"; /* 6to4 mapping for "192.0.2.4" */
set var.ip = "::FFFF:192.0.2.4"; /* IPv4 mapping for "192.0.2.4" */
set var.ip = "::1";
set var.ip = "::"; /* unspecified address */

Short forms for IPv4 are not permitted:

declare local var.ip IP;
set var.ip = "192.2.0"; /* invalid; would be equivalent to "192.0.2.0" */
set var.ip = "127.1"; /* invalid; would be equivalent to "127.0.0.1" */
set var.ip = "0"; /* invalid; would be equivalent to "0.0.0.0" */