Hi Erwin, Sorry, I don't understand why it breaks zone transfers when the serial is higher. Could you show me the zone configuration? We only changed `zonefile-load: difference'. Daniel On 9/24/26 11:23, Erwan David wrote: > On Thu, Sep 24, 2026 at 10:04:28AM CEST, Erwan David <erwan(a)rail.eu.org> said: > > Since upgrade to knot 3.6, when I restart the knot server, a new serial is generated for the secondary zones, > > putting them out of sync with the primary. > > > > Logs in 3.5 > > > > Aug 25 10:31:50 ns knot[45038]: info: [domain.] zone will be loaded > > Aug 25 10:31:51 ns knot[45038]: info: [domain.] zone loaded from journal, serial 2026023115 > > Aug 25 10:31:51 ns knot[45038]: info: [domain.] zone file loaded, serial updated 2026023115 -> 2026082500 > > Aug 25 10:31:51 ns knot[45038]: info: [domain.] loaded, serial none -> 2026082500 -> 2026023115, 21088 bytes, expires in 2137390 seconds > > > > Last line show the serial is set back to the serial of the journal loaded zone > > When starting 3.6 > > > > Sep 24 07:49:14 ns knot[23114]: info: [domain.] zone will be loaded > > Sep 24 07:49:14 ns knot[23114]: info: [domain.] zone loaded from journal, serial 2026023175 > > Sep 24 07:49:14 ns knot[23114]: info: [domain.] zone file loaded, serial updated 2026023175 -> 2026092400 > > Sep 24 07:49:14 ns knot[23114]: info: [domain.] loaded, serial none -> 2026092400, 21088 bytes, expires in 2158298 seconds > > > > The serial is not set back to the serail from the journal. As you can see in this case the primary does not use a date based serial number, > > thus the secondary is then out of sync and refuses the notifications > > Ok, I was in zonefile-load: difference-noserial and the behaviour changed with 3.6 > I corrected it

Thanks (The correct value is `difference-no-serial`). Probably it's a result of "knotd: enforced serial policy during initial zone file load if 'difference-no-serial' is enabled". We will check this case. What was your correction, removal of `serial-policy: dateserial`? Daniel