The IP Database can pass reverse DNS information back and forth to a DNS management backend to simplify maintenance of the reverse DNS records associated with the IPs being managed.
Several shortcuts can be used when specifying a pattern for an IPv4 netblock, which will be expanded to actual DNS records by the DNS management system. %blank% may be used to skip template expansion on a subblock or IP.
Entries should generally only be present in the "Per-IP reverse entries" section if they are different from the block pattern.
Template patterns are not supported for IPv6 allocations due to the size of the address space and typical size of allocations.
| Substitution pattern | Example expansion using 192.168.23.45 | |
| Whole-IP patterns | ||
| Dashed IP | %i | 192-168-23-45 |
| Reverse dashed IP | %r | 45-23-168-192 |
| Hex-coded IP | %h | c0a8172d |
| Decimal IP | %d | 323241453 |
| Per-octet patterns (1, 2, 3, or 4 specify the octet; d, h or 0 specify decimal, hexidecimal, or 0-padded decimal) | ||
| First octet, decimal | %1d | 192 |
| Third octet, 0-padded | %30 | 023 |
| Fourth octet, hexidecimal | %4h | 2d |
| All octets, different expansions | %1h-%2d-%30-%4h | c0-168-023-2d |
%i and %r also allow explicitly defining the separator; eg %.i
or %_r. '.', '-', and '_' are the only characters
supported since DNS names may not contain most other
non-alphanumerics.