According to the Forescout Switch Plugin Configuration Guide Version 8.12 and 8.14.2, when troubleshooting a failed change VLAN action, you should verify: "The Switch Model is compatible for the change VLAN action, The managing appliance IP is allowed write VLAN changes to the switch, The network infrastructure allows CounterACT SSH and SNMP Set traffic to reach the switch, The action is enabled in the policy".
Troubleshooting Switch VLAN Changes:
According to the Switch Plugin documentation:
When a VLAN assignment fails, verify:
Switch Model Compatibility
Not all switch models support VLAN changes via SNMP/SSH
Consult Forescout compatibility matrix
Refer to Appendix 1 of Switch Plugin guide for capability summary
Managing Appliance Permissions
The managing appliance must have write access to VLAN settings
Requires appropriate SNMP community strings or SNMPv3 credentials
Must be allowed to execute SNMP Set commands
Network Infrastructure
SSH access to the switch (CLI) - typically port 22
SNMP Set traffic to the switch - port 161
NOT "SNMP Get" (read-only) or "SNMP Trap" (notifications)
SNMP Set is specifically for write operations like VLAN assignment
Policy Action Status
The action must be enabled in the policy
If the action is disabled, it won't execute regardless of other settings
Why Option C is Correct:
According to the documentation:
✓ Switch Model (not Vendor) - Model-specific capabilities matter
✓ Managing appliance (not Enterprise Manager) - For distributed deployments
✓ SNMP Set (not Get or Trap) - Required for write/change operations
✓ Action enabled (not disabled) - Prerequisite for execution
Why Other Options Are Incorrect:
A - Mixes incorrect items: "action is disabled" is wrong; "SNMP Trap" is for notifications, not VLAN changes
B - States "SNMP Get" (read-only) instead of "SNMP Set" (write); has "action is disabled"
D - Says "all actions" instead of "change VLAN action"; uses "SNMP Set" correctly but other details wrong
Referenced Documentation:
Forescout CounterACT Switch Plugin Configuration Guide v8.12
Switch Plugin Configuration Guide v8.14.2
Switch Configuration Parameters
Switch Restrict Actions
