The length of the CIDR Prefix carried in
hh3cPortalFreeRuleSrcAddr. In IPv4 addresses, a length of 0
indicates a match of any address; a length of 32 indicates a
match of a single host address, and a length between 0 and 32
indicates the use of a CIDR Prefix. IPv6 is similar, except that
prefix lengths range from 0..128.