You say a browser is not at the application layer? Where would you put it? Or Email, or Any app on your phone? For me these are surely Layer 7 applications that require: 1-pysicial connection, 2-mac address, 3, ip add, 4, port #, 5 Session support (DNS, Login, NFS/SMB) 6-Data formatting.

​@@maxquasar Soooo a browser is a network aware application that uses an application protocol such as HTTP to pass the data. I do teach uni networking and its a very very common misconception that application layer is the application itself. Another example is you could have a file sharing application such as filezilla and then choose to use application layer protocols such as ftps, sftp, ftp to pass your data down the network stack. Now with the browser application example the upper layers (application, presentation, session) typically happen inside the browser then the lower layers get handed off to OS

@@saria-dq5gc You make such an interesting point! I had to scratch my head and defer to my Assistants; ChatGPT, Claude & Bard. While all agreed with me, they also did recognize your point and Claude especially was kind to your view (please forgive my calling you a student. I would also consider you a teacher as well) "You raise an interesting question about where web browsers fit within the TCP/IP and OSI network models. The student's perspective is thought-provoking, but I would argue that web browsers are indeed part of the application layer in both models. Here's my reasoning: The application layer is the topmost layer in both the TCP/IP and OSI models. It is responsible for providing services directly to the end-user applications. Web browsers, being end-user applications, naturally fit into this layer. Protocols like HTTP, FTP, and SMTP are all application layer protocols. They define the rules and formats for data exchange between applications. Web browsers use HTTP to communicate with web servers, making them a part of the application layer. The TCP/IP and OSI models are conceptual frameworks that help us understand how data is transmitted over networks. They do not necessarily dictate a strict hierarchy of applications above the models. Placing web browsers above these models would imply that they operate independently of the underlying network protocols. However, web browsers heavily rely on the application layer protocols (like HTTP) and the lower layers for their functionality. That being said, the student's perspective isn't entirely baseless. One could argue that web browsers, along with other high-level applications, form a separate "user layer" above the application layer. This user layer interacts with the application layer protocols to provide a user-friendly interface. However, this concept is not part of the standard TCP/IP or OSI models. In summary, while the student's viewpoint is interesting, it deviates from the widely accepted understanding of the TCP/IP and OSI models. Web browsers, as end-user applications relying on application layer protocols, are best placed within the application layer of these network models.

Thank you very much.

​@@maxquasar Yes Sir going thru a Mid Life Career Transition, after 50 and being a so-called Minority in this Country, you need all of the New Updates on Technology that you can get in order to stay competitive in this High-Tech Job Market. Everything I learn in school back in the 90s is over and obsolete. I have to totally Revamp my Self. Even my Looks and Posture. I have to keep Working Out, Staying Slim. I had to quit Drinking and Smoking, suspend bad eating habits, all have to go if you still have to work in the office after 50. By You making these classes easy online is great. Thanks for sharing.

You’re not wrong, but in this case active refers to taking actions to limit further damage, similar to the difference between and IDS and an IPS. Still, to your point most/all SIEM vendors have plugins for this too but to most, these are listed as SOAR features 🖖

got your point, I had to read it again, thanks.@@maxquasar

It is true that Smurf uses ICMP to create a DDoS and if "Covert Channel" wasn't there it might have been the "best" answer provided. Thank you for the comment, -Larry 🖖

What a great question! In this question, please notice that the context is “After the implementation of a required control” so this suggests that the scope was met already. The issue here is can it be configured to be closer to the baseline so it wasn’t too far out of scope. All controls add “friction”. I can surely see how answer 1, may result in users pointing out that things seem slow is useful in the process, I think answer 4 is still better and refers something along the lines of take measurements of “Scrap” at CMMI level 4, to reach better business process alignment at CMMI level 5. Still a great question and I wonder if I couldn’t have worded the question better. Thank you very much. -Larry

Hi Larry, baselines are not set AFTER implementation of controls. That's too late.