CSUMB CS Online Learning Journal - Ryan

 This week, I explored the basics of operational security implementation. The focus was on firewalls and intrusion detection systems (IDS). I learned how firewalls are the first line of defense, filtering traffic based on predefined rules. IDS systems monitors network activity for signs of malicious behavior, adding an additional layer of protection. Understanding the role of these tools is critical for securing network infrastructures.  We also completed our final team programming assignment which was to develop TLS-enabled servers on a Mininet network. This involved setting up a Mininet network and modifying a provided Python starter file. The main task of the assignment was to implement a group chat feature on top of the simple chat we created in the team programming assignment three. We also implemented the certificate authority (CA) to enable secure communication between the server and clients.

 This week, I delved into key concepts of the link layer, beginning with the principles behind its services. I learned about error detection and correction techniques, such as parity checks and cyclic redundancy checks (CRC), which are vital for ensuring data integrity during transmission. Multiple access protocols, including ALOHA and Carrier Sense Multiple Access (CSMA), were also a focus, helping me understand how devices share a broadcast channel in a network and avoid collisions. The use of ARP for link layer addressing was explored using Wireshark, providing hands-on experience with how ARP maps IP addresses to MAC addresses. I also explored Ethernet technologies, examining how link layer switches and VLANs segment and manage networks more efficiently. This led me to investigate Layer 2 devices and their role in network segmentation using a Python-based SDN controller in Mininet. The hands-on emulation of a four-network, three-router topology using the Mininet API further sol...

 This week, we developed a deeper understanding of the network control plane and explored routing algorithms such as Dijkstra and Bellman-Ford, focusing on how they determine the most efficient paths for data transfer. We also learned about the SDN control plane, which allows for dynamic network management and routing. In addition to the theory learned this week, we conducted a network lab exploring the use of a basic SDN controller using Mininet and Wireshark. We looked at how Internet Control Message Protocol (ICMP), can be used for network diagnostics, particularly for network troubleshooting with tools like ping and traceroute.

 This week we learned about the network layer and focused on the data plane. I learned about two important concepts which was forwarding and routing. Forwarding, dealing with how data packets are moved between devices in a network, and routing, which determines the paths the data packets take across networks. In our lab assignments we learned about Network Address Translation (NAT), which allows communication between private network devices over public networks. The big assignment this week was our group programming assignment, the server chat program. I found this assignment to be particularly interesting because it provided me with a very basic but fundamental understanding of how chat programs are built.