While committing any changes on the master RE and configuration is in "protected" mode, the config is not synchronised and change is not reflected on backup RE.

Example:

Master:

labroot@jtac-mx480-r2013-re0> show system rollback compare 0 3

[edit interfaces ae10]

+  protect: unit 963 {

+    description "[106312269][CORP][ILL][VNM-VL3651][TOA HTC-HOALAC]";

+    vlan-id 963;

+    family inet {

+      filter {

+        output ILL-VNM-VL3651;

+      }

+      address 113.20.96.77/30;

+    }

+    family inet6 {

+      address 2402:5300:404:a::/127;

+    }

+  }

{master}

labroot@jtac-mx480-r2013-re0> show configuration | display set | count

Count: 37701 lines

{master}

labroot@jtac-mx480-r2013-re0> show configuration interfaces ae10 unit 963| display set

Backup:

{backup}

labroot@jtac-mx480-r2013-re1> show configuration | display set | count

Count: 37707 lines

{backup}

labroot@jtac-mx480-r2013-re1> show configuration interfaces ae10 unit 963 | display set

set interfaces ae10 unit 963 description "[106312269][CORP][ILL][VNM-VL3651][TOA HTC-HOALAC]"

set interfaces ae10 unit 963 vlan-id 963

set interfaces ae10 unit 963 family inet filter output ILL-VNM-VL3651

set interfaces ae10 unit 963 family inet address 113.20.96.77/30

set interfaces ae10 unit 963 family inet6 address 2402:5300:404:a::/127

protect interfaces ae10 unit 963

As per current behaviour, first "unprotect" the config/interface in first commit and later modify the config in next commit.

When "unprotect" and config change both are done in single commit then "unprotect" is NOT sent to backup RE and hence this behaviour is observed where configuration gets out-of-sync with backup RE.