A Zone Transfer Question

[David Li]

 This is my first time to try master slave configuration. Here is a
    brief description:

    I have two Centos 7.1 VMs - each is configured for a zone. VM1 is the
    master for zone1 and slave for zone2. VM2 is master for zone2 and
    slave for zone1. Both zones uses DNS Dynamic Update from DHCP
servers on the same VM
    to update the A records in their zone files. No DNSSEC configured.


    To start, everything seems to be working fine. I have one host in each
    zone and they can resolve each other fine.

    Now I add a new host to zone1 and its sequence number has been bumped
    up. I read that when the zone1 file changes, it will automatically
    notify its slave zone (ie. zone2) to start a zone transfer after 15
    min. This never happened. Then I restarted named on VM2 and hoped it
    would pull the new zone1 file. This didn't happened either.
    Eventually I have to either restart the VM2 or use dig to start the
    zone transfer.

    Can anyone spot anything obviously wrong here? Do I need to post my
    zone file and named.conf?


    Thanks.

    David