Last Modified: Apr 28, 2025
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
11.5.4
Opened: Apr 18, 2016 Severity: 3-Major Related Article:
K17345740
Under certain conditions, monitor instances can be deleted in a peer unit after an incremental sync.
Pool members in the affected pool are no longer monitored in the peer unit. And due to the inconsistency in the number of monitor instances, upcoming configsync operations might fail with an error similar to this one: 'Caught configuration exception (0), Invalid monitor rule instance identifier: [id]'.
The issue is triggered by disabling a pool member or a node (either though the Configuration Utility or a tmsh command, as in 'tmsh modify ltm node [nodename] state user-down'), followed by an incremental configsync. As a result, the peer device will delete all the monitor instances associated to all the pool members from the pool to which the disabled member belongs.
The full sync operation is not affected by this issue. As a mitigation, a 'tmsh load sys config' in the affected unit will reload all the monitor instances that disappeared.
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