dhcp issue

Internet Systems Consortium DHCP Server 4.3.3
Copyright 2004-2015 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
Config file: /etc/dhcpd.conf
Database file: /var/db/dhcpd.leases
PID file: /var/run/dhcpd.pid
Can't open lease database /var/db/dhcpd.leases: Permission denied --
  check for failed database rewrite attempt!
Please read the dhcpd.leases manual page if you
don't know what to do about this.


請參考
https://help.ubuntu.com/community/isc-dhcp-server