forcing zone file update with DDNS

[Jim Reid]

>>>>> "Jeff" == Jeff Layton <jtlayton at pliantsystems.com> writes:

    >> It does periodically write out the zone.

    Jeff> How often is periodically (roughly)? Are we talking every 30
    Jeff> mins or once a day?  

Did you try reading the source code? From ns_defs.h:

#ifdef BIND_UPDATE
#define SOAINCRINTVL 300 /* default value for the time after which
                          * the zone serial number must be incremented
                          * after a successful update has occurred */
#define DUMPINTVL 3600   /* default interval at which to dump changed zones
                          * randomized, not exact */
#define DEFERUPDCNT     100     /* default number of updates that can happen
                                 * before the zone serial number will be
                                 * incremented */
#define UPDATE_TIMER XFER_TIMER
#endif /* BIND_UPDATE */


    Jeff> I'd hate to do a buncha updates and then lose them...  -- JL

That's why the name server writes out new updates to a .log
transaction log file. It contains the dynamic updates which have been
made to the zone since the last time a new zone file was written
out. This allows the name server to roll forward by merging the old
zone file with the transaction log to get the zone back to the state
it was in before the name server crashed or whatever. So after
approx. 1 hour, a new zone file is written out and the transaction log
zapped because its updates have been incorporated into the new zone
file. This means you should only lose updates if the filesystem loses
files.