On Mon, May 09, 2011 at 02:37:04PM +0800, Jeff Pang <jeffrpang at gmail.com> wrote a message of 14 lines which said: > which port is used by BIND for nsupdate? 53 by default, the standard port. nsupdate is for Dynamic Update, which uses the regular DNS protocol (unlike rndc which uses a BIND proprietary protocol).