Comprehensive and Detailed Explanation From Exact Extract of Forescout Platform Administration and Deployment:
According to the Forescout Installation Guide and Working with Appliance Channel Assignments documentation, a Layer-2 channel "Utilizes two interfaces" - one monitor interface and one response interface.
Layer-2 Channel Structure:
According to the documentation:
"A channel defines a pair of interfaces used by the Appliance to protect your network. In general, one interface monitors traffic going through the network (the monitor interface), and the other responds to traffic on the network (the response interface)."
Two Interface Components:
According to the Installation Guide:
Monitor Interface:
Monitors and tracks network traffic
Traffic is mirrored from switch ports
No IP address required
Can be any available interface
Response Interface:
Responds to monitored traffic
Used for policy actions and protections
Configuration depends on VLAN tagging
Can be same VLAN or trunk configuration
Layer-2 vs. Layer-3 Channel:
According to the documentation:
Layer-2 Channel - Two interfaces (monitor and response)
Layer-3 Channel - Uses IP layer for response
Why Other Options Are Incorrect:
A. Recommended for large number of VLANs - Actually, Layer-2 channels with VLAN tagging are recommended for multiple VLANs, but this doesn't define what a Layer-2 channel is
B. Response interface is a VLAN trunk - While response interface CAN be a trunk for multiple VLANs, it's not required for all configurations
C. Monitor interface is a trunk - The monitor interface receives mirrored traffic; trunk configuration depends on VLAN setup
E. Must be connected to access layer switch - The appliance can connect to various switch types; not specifically limited to access layer
Referenced Documentation:
Working with Appliance Channel Assignments
Quick Installation Guide v8.4
Quick Installation Guide v8.2
Add Channels
Monitor Interface
Set up the Forescout Platform Network
