Chapter 4: TCP/IP

Note: I give. Trying to make this a "real blog" with NaNoWriMo, a second class, and the busiest time of year at work (I work in retail - one of the reasons for taking this class in the first place - so I can get into a career field that's more cerebral and more lucrative) pressing down on me is proving to be a bit too much. Until I get caught up, these blog posts are going to be much shorter and less in-depth than the previous ones. If I get a chance, I may go back and crank them up to a higher level, but for now, I just need to complete the assignments.

TCP/IP is the suite of protocols that most modern networks (including the internet) run on. However, despite the name, it's more than just TCP and IP - the suite also includes protocols like UDP (useful in applications like VOIP) and the ARP/RARP protocols used for address resolution. Basically, TCP/IP is the language that allows a network to communicate. TCP and UDP to move data around, ARP and RARP to establish addressing, ICMP to report any problems with the path the packets are taking, and so forth.

The chapter also covered addressing. The web currently runs on IPv4 (an IPv4 address looks like this: 192.168.24.130) this is all well and good, but the addresses are getting used up at a rapid pace. One solution to this is IPv6, which has a lot more available address space (79,228,162,514,264,337,593,543,950,336 unique addresses as opposed to IPv4's approximately 4.3 billion, to be precise). One stopgap measure that's been used is private network IPs, which means that you can re-use a block of IPs as long as they're not connected to the larger internet. My router at home, for example, uses the 192.168.x.x IP space. So does everybody else who uses that type of router's network. The router itself, however, uses a public IP issues by my internet service provider.

The chapter also covered DNS or Domain Name Service, which is nothing more, and nothing less, than the process which turns www.mchenry.edu into the IP address that will direct my web browser to the college's web page.

An interesting chapter from a theoretical point of view. I was dimly aware of TCP/IP, DNS and the like when I started reading (thanks largely to the early episodes of Security Now) but this got a lot more in depth.