It doesn't have to break on the octet either; for example, the network I'm on now has a subnet mask of 255.255.252.0.
Another way you'll see this notated is called CIDR notation, which looks like 10.10.20.0/24. The "24" is equivalet to 255.255.255.0, because it means the first 24 bits of the IP is the network. My subnet mask of 255.255.252.0 would be /22 in CIDR notation.
The way we currently accomodate billions of connected devices is by putting the vast majority of them on a private IP range behind a NAT. Getting an actual public IP usually involves some expense, and we're running out of them. This is why you'll see people pushing for ipv6, which adds a lot more addresses and does away with the need to NAT and do private addressing.The principle reason why devices on networks are usually assigned IPs and masks is because, so the internet’s architects reasoned, it would be mathematically impossible for every device to have a unique address because there are more devices than are available IP addresses:
The multiplication in the first set of brackets represent Class A, the second set represents Class B and the third, Class C. Class D is multicast and E is reserved. CIDR and IETF in 1993 introduced IPv4, among other things, including subnet masking for the purposes of providing billions of additional address combinations to accommodate for the more than 3.5 billion devices/servers/gateways demanded by consumers, businesses and governments.Code:(16,000,000×127)+(65,000×16,000)+(254×2,000,000) = 3,580,000,000
Is all that accurate?
Actually most network-connected devices these days does have a dhcp client built in; I'd say most printers I've seen for at least the last decade can do DHCP. It's probably a good idea to assign a static IP so you know where to send your print jobs, though.#2
After installing an all-in-one printer/fax/copier, does it use an APIPA address until the network admin assign it a more permanent address using the gateway router’s firewall firmware? And please correct me if I am wrong, but most all-in-one printer/fax/copiers usually don’t have a DHCP client installed to use to exchange a lease agreement. This means that a network admin has to assign it a static IP. Is that accurate?
Only if it is an officially registered port number. See https://en.wikipedia.org/wiki/List_o...P_port_numbers#3
Wikipedia says that IANA is responsible for the global coordination of the DNS Root, IP addressing, and other Internet protocol resources. *Is IANA the body (which would be many years ago now) that decided that FTP would use port 21, http use port 80, and irc port 194? *Is it also possible that Valve software, for their first multiplayer game they wrote (Half-Life) back in 1997, was told by IANA to use port 27015?
If you want to go into IT (I don't know why you'd want an A+ if you didn't), it's best to get these concepts straight whether or not they're on the exam. Every computer is networked these days, there isn't much point in a tech who doesn't understand networking.Some of you might be thinking, ‘why is this person asking CCNA/Network+ questions when he is preparing to write his A+ exams’? There are 3 chapters in both of my A+ texts devoted to networking. These chapters in particular I struggled with the most, compared to all the other chapters on PC repair and such. I am working on my weakest link by trying to understand these basic network concepts....