An engineer is vorlang on a LAN switch and has noticed that its network connection to the mime Cisco IPS has gone down Upon troubleshooting it is determined that the switch is working as expected What must have been implemented for this failure to occur?
A. The upstream router has a misconfigured routing protocol
B. Link-state propagation is enabled
C. The Cisco IPS has been configured to be in fail-open mode
D. The Cisco IPS is configured in detection mode
