could not listen on UDP socket: permission denied

自從家裡的老 server 爆炸，然後應爹娘要求儘速處理，於是展開移山倒海 shift 大法，把比較省電且輕巧的小白 (AM2 X2 3800+) 給帶回去暫時先把網路搶通後就沒空理他，今天上去一看發現 message 一直出現：

May 9 04:19:11 soul named[960]: could not listen on UDP socket: permission denied
May 9 04:19:11 soul named[960]: creating IPv4 interface tun0 failed; interface ignored
May 9 05:19:11 soul named[960]: could not listen on UDP socket: permission denied
May 9 05:19:11 soul named[960]: creating IPv4 interface tun0 failed; interface ignored
May 9 06:19:11 soul named[960]: could not listen on UDP socket: permission denied
May 9 06:19:11 soul named[960]: creating IPv4 interface tun0 failed; interface ignored
May 9 07:19:11 soul named[960]: could not listen on UDP socket: permission denied
May 9 07:19:11 soul named[960]: creating IPv4 interface tun0 failed; interface ignored
May 9 08:19:11 soul named[960]: could not listen on UDP socket: permission denied
May 9 08:19:11 soul named[960]: creating IPv4 interface tun0 failed; interface ignored
May 9 09:19:11 soul named[960]: could not listen on UDP socket: permission denied

詢問了 google 大神之後發現大概是 這麼一回事 ，所以就乖乖的照著 mac_portacl(4) 去把 kernel configuration 的 options MAC 加進去，然後到 /boot/loader.conf 加入 mac_portacl_load=”YES” 接著照著 handbook 的 example 依樣畫葫蘆塞進 sysctl security.mac.portacl.rules=uid:53:udp:53,uid:53:tcp:53 然後重新啟動囉。