G-Series, firmware 6.61.02.0007 through 6.61.08.0013
C5-Series; firmware 6.61.02.0007 through 6.61.08.0013, 6.61.07.0010 through 6.71.02.0008
C3-Series, firmware 6.61.02.0007 through 6.61.08.0013
B5-Series; firmware 6.61.02.0007 through 6.61.08.0013, 6.61.07.0010 through 6.71.02.0008
A4-Series; firmware 6.61.02.0007 through 6.61.08.0013, 6.61.07.0010 through 6.71.02.0008
Created a SNTP management interface (5573) for a VLAN interface that is not operational.
Example: 'set sntp interface vlan 4'
Output of 'show system utilization' indicates a high CPU utilization percentage for the "SNTP" task.
The SNTP task is attempting communication on a VLAN interface that is not operationally up. This causes the process to hang, which increases CPU utilization.
Upgrade to 6.61 firmware 6.61.09.0012 or higher.
Release notes state, in the 'Changes and Enhancements in 6.61.09.0012' section:
Addressed high CPU utilization resulting from shutting down a routed SNTP interface.
Also fixed in C5/B5/A4 firmware 6.71.03.0025 or higher (though not stated in release notes).
Ensure that the selected interface is operational (loopback interfaces are by definition always operational), or do not use the interface command for SNTP configuration.