CST311 - Week 36

This week we covered sections 4.1 - 4.4, covering the data plane of the network layer. We learned the definitions of forwarding and routing and learned about the components of a router: input ports, switching fabric, output ports, and a routing processor. We then delved into the details of IPv4 including its format, fragmentation process, and addressing. We read about DHCP and the process of obtaining a host address, which was highlighted in Lab 8. Network Addressing Translation (NAT) helps with address allocation with a NAT-enabled router that appears with a single IP address to hide details of a home or small office network, which also helps circumvent the issue of not enough address space. We then discussed IPv6 and its differences, as well as how tunneling is used with putting an entire IPv6 datagram in the payload of an IPv4 datagram. Lastly, we discussed forwarding and SDN with a focus on OpenFlow.

In Lab 7 we observed the NAT protocol and the way it translates IP addresses and ports. In this lab, we captured packets from two different places, the "LAN" side - NAT-adaptor - and the "WAN" side - host computer.

Lab 8 was very interesting. Using Wireshark we were able to capture packets and clearly see the DHCP release, discover, offer, request, and ACK messages. It really helped bring the textbook to life with a visual example.