Digital Router Question:

For the IP address that most people are familiar with (IPv4), there are 4 sets (octets) of numbers, each with values of up to 255. You likely have run into this when troubleshooting a router or a DHCP server, when they are giving out addresses in a particular range- usually 192.x or 10.x in the case of a home or commercial network. IP classes are primarily differentiated by the number of potential hosts they can support on a single network. The more networks supported on a given IP class, the fewer addresses are available for each network. Class A networks run up to 127.x.x.x (with the exception of 127.0.0.1, which is reserved for loopback or localhost connections). These networks are usually reserved for the very largest of customers, or some of the original members of the Internet and xkcd has an excellent map (albeit a bit dated) located here showing who officially owns what. Class B (128.x to 191.x) and Class C (192.x to 223.x) networks are much more fuzzy at the top level about who officially owns them. Class C addresses are primarily reserved for in-house networks which is as we mentioned above why so many different manufacturers use 192.x as their default setting. Class D and E are reserved for special uses and normally are not required knowledge.