Exam CISSP topic 1 question 475 discussion

A. Session layer

D is the correct answer.

layer 5. Session

Stupid and illogical question. From OSG (pg. 553). Circuit-Level Firewalls Circuit-level firewalls (aka circuit proxies) are used to establish communication sessions between trusted partners. 'In theory', they operate at the Session layer (layer 5) of the OSI model (although 'in reality', they operate in relation to the establishment of TCP sessions at the Transport layer [layer 4]).

Answer: A. Session layer https://www.datamation.com/networks/circuit-level-gateways-definition-features-examples/#:~:text=A%20circuit%2Dlevel%20gateway%20is,between%20end%2Duser%20application%20processes.

Stateless Firewall: Layer 3 network Stateful: Layer 3 and 4, network and transport Circuit level: Layer 5 Session Aplication level: Layer 7 Application (proxy)

A circuit-level firewall operates at the Session layer (Layer 5) of the OSI model.

Circuit-level firewalls operate at the Session layer (Layer 5) of the OSI model rather than the Network layer (Layer 3) .

I find this question to be a little tricky. Here is the reason why the answer is A and not B: Circuit-level firewalls operate at the Session layer (Layer 5) of the OSI model rather than the Network layer (Layer 3). Here's why: +Circuit-level firewalls work at the TCP session level, protecting established sessions between hosts. +The Session layer (Layer 5) deals with establishing, managing, and terminating connections between two communicating hosts. -The Network layer (Layer 3) deals with IP addresses and routing packets towards their destination. - Packet-filtering firewalls operate at Layer 3 as they simply filter packets based on source/destination IP addresses, ports, protocols.

Session Layer, https://en.wikipedia.org/wiki/Circuit-level_gateway

Agree with A

Correct answer is A