Exam 156-587 Topic 5 Question 46 Discussion

The fw monitor command is a powerful troubleshooting tool in Check Point Gateways that captures packets at various points in the processing chain. The question asks how to capture traffic pre-inbound (before inbound processing, i.e., at the "i" inspection point) and before the VPN module (before VPN decryption or processing).
The fw monitor syntax allows specifying inspection points using options like -pi (pre-inbound) and module names (e.g., -vpn for the VPN module). The correct syntax to capture traffic before a specific module is -pi -<module>, where the module name is prefixed with a minus sign to indicate "before" the module.
Option A: Incorrect. fw monitor -p all captures packets at all inspection points in the chain, which includes pre-inbound, post-inbound, pre-outbound, and post-outbound points, as well as points around all modules. This is too broad and does not specifically target pre-inbound and before the VPN module.
Option B: Correct. fw monitor -pi -vpn captures packets at the pre-inbound inspection point ("i") and before the VPN module (-vpn). The -pi specifies the pre-inbound point, and -vpn ensures the capture occurs before VPN processing (e.g., decryption).
Option C: Incorrect. fw monitor -pi +vpn would capture packets at the pre-inbound point but after the VPN module (+vpn indicates after the module), which contradicts the requirement to capture before the VPN module.
Option D: Incorrect. This option is a duplicate of Option C in the provided question, likely a typographical error. Even if corrected, +vpn is incorrect for the same reason as Option C.
Reference:
The Check Point R81.20 Gaia Administration Guide explains the fw monitor command and its options, including how to specify inspection points and module positions. The CCTE R81.20 course includes hands-on labs for using fw monitor to troubleshoot packet flow, emphasizing precise inspection point selection.
For precise details, refer to:
Check Point R81.20 Gaia Administration Guide, section on "fw monitor" (available via Check Point Support Center).
CCTE R81.20 Courseware, which covers advanced packet capture techniques with fw monitor (available through authorized training partners).