ports/net/miniupnp/miniupnpc/pkg

+-----------------------------------------------------------------------
| Running ${PKGSTEM} on OpenBSD
+-----------------------------------------------------------------------

For proper functionality, multicast(4) needs to be enabled. To do so,
add the following line to /etc/rc.conf.local(8):
    multicast=YES

Otherwise, local LAN IP address must be specified on the upnpc command
line, using the '-m' option. e.g.:

$ upnpc -m 192.168.2.78 -l