Further details on these packages:
The OpenBSD port for ISC's reference implementation of DHCP is
net/isc-dhcp. It has three packages available: a DHCPd server (isc-dhcp-server), a DHCP client (isc-dhcp-client) and a relay agent (isc-dhcp-omapi). For OpenBSD 5.5-release, this is ISC's version 4.2.5-P1. For OpenBSD 5.6, which will be released on November 1, it is version 4.3.0.
The OpenBSD port for PowerDNS is
net/powerdns. There are four packages, depending on the backing database: powerdns, powerdns-ldap powerdns-mysql, and powerdns-pgsql. For OpenBSD 5.5 and 5.6, this is version 2.9.22.6.
For more on packages and ports, see
FAQ 15.