{"id":2373,"date":"2015-10-20T14:19:16","date_gmt":"2015-10-20T13:19:16","guid":{"rendered":"https:\/\/stevepedwards.today\/DebianAdmin\/?p=2373"},"modified":"2025-12-30T18:41:17","modified_gmt":"2025-12-30T23:41:17","slug":"when-beginners-ask-whats-an-ip-address","status":"publish","type":"post","link":"https:\/\/stevepedwards.today\/DebianAdmin\/when-beginners-ask-whats-an-ip-address\/","title":{"rendered":"When students ask: What's an IP Address?"},"content":{"rendered":"
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As a support tutor of beginner level IT students of vastly different ages and backgrounds, I sometimes have to refresh and evaluate my own knowledge and approach to a certain topic that arises, so I find writing Posts like this helpful to organise ideas on subjects that I had difficulty understanding myself, to see if I can explain or expand on things better, or a bit differently than how I learned or was taught.<\/p>\n

I try to get a lot more across, more efficiently, so a bigger picture emerges for a student even if less detailed or well understood in the short term - rather than forcing a parrot fashion cop-out by lazy lecturers approach, along the: \"you just need to accept and learn this, as it will become clearer later\" approach but without overtaxing them or myself in the available time.<\/p>\n

Recently I got asked;<\/p>\n

\"What is an IP Address?\"<\/p>\n

A perfectly sensible question for any IT student to ask but from a teachers perspective, it not so easy to answer for many reasons.<\/p>\n

Answering this (or anything really) mainly depends on how much available time there is and the relative knowledge level, curiosity and ability of the student.<\/p>\n

For example, depending on the situation; do I mention IPV4 address format related to 32 bit binary, memory and bus technology evolution?<\/p>\n

Subnetting - why its required?<\/p>\n

Binary ANDing and 32 bit number space limitations, CIDR and God forbid IPv6?!<\/p>\n

Why TCP\/IP is used and not other methods, so DARPANET as the Internet's beginnings?<\/p>\n

The most concise but least illuminating answer at this point is usually similar to:<\/p>\n

An Internet Protocol address is a unique<\/i> numerical identifier for a computer on a given network.<\/p>\n

This will probably be followed by a how? or why? type question.<\/p>\n

For the why type, I give an analogy of the unique name\/house number\/street of a postal system address or similar.<\/p>\n

For the how type, I mention a certain type of server (DHCP) as a special computer that hands out a unique number to a computer when its attached to a network.<\/p>\n

If I go down the route of explaining the format of an IP address such as 192.168.1.10<\/b>, I may have to include the idea of a subnet - which can get messy without students getting perspective on the whole available address space of IPV4, because the number format itself does not make sense to the student at this point, in terms of why its unique, and what the dots mean. If they see an example with a \/24 after it you really have your work cut out...<\/p>\n

To explain any of that in any meaningful, satisfying way, they need to understand the conversion of the decimal numbers to binary that multiply out the total number space, which is usually where I start, then gauge when and if eyes are starting to glaze over\u00a6<\/p>\n

Starting with binary, I win either way: either I find a student worth the time and effort, or they change the subject and\/or run away.<\/p>\n

Each of the four dot delimited decimals in 192.168.1.10 <\/b>are an 8 bit byte binary number, so each byte can have a value between 0 and 255 for each of the four decimal blocks ranges of numbers they contain:<\/p>\n

\"\"<\/p>\n

Now it can be seen that an 8 bit binary number range can contain a maximum of (2^8 - 1) numbers = 0-255 in decimal.<\/p>\n

Now the idea can be extended to the example IP address 192.168.1.10 say - so that the student can see that the total numerical address space of IP4 (0-255.0-255.0-255.0-255) would comprise four blocks of 256 addresses (0-255), giving a total of 256 x 256 x 256 x 256 or 2^32 individual numbers = 4,294,967,296 unique numbers. I have to omit network and host separation concepts at this point.<\/p>\n

This enables a student to realise, theoretically, that there is a maximum number of computers that could be connected to the same theoretical network, and no more, and that this is a major technical shortcoming of IP4, as the original designers never foresaw the explosion in Internet popularity as has occurred, that would require more address IDs than this 32 bit space allows (2^0 to 2^31). They probably didn't foresee 64 bit computers evolving so soon after about 1998 either?<\/p>\n

As there are now more physical computers\/phones on the planet than 4.3 billion, that may need to connect to the Internet at the same time, so would not get a unique ID if the Internet really was one big network, they are sub-divided into smaller, locally manageable sections, or sub-networks, that use various clever methods to extend the seemingly finite available address space of 2^32 unique numbers.<\/p>\n

The increase in Internet usage toward this 32 bit maximum number is shown nicely below with about 1 billion IP4 numbers left available:<\/p>\n

https:\/\/www.internetworldstats.com\/stats.htm<\/a><\/p>\n

 <\/p>\n\n\n<\/colgroup>\n\n\n\n\n
\n

<\/a> World Internet Users and 2015 Population Stats<\/b><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

<\/td>\n<\/tr>\n
<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n\n\n<\/colgroup>\n\n\n
 <\/p>\n\n\n<\/colgroup>\n\n\n
 <\/p>\n\n\n\n\n\n\n\n\n<\/colgroup>\n\n\n\n\n\n\n\n\n\n\n\n\n
\n

WORLD INTERNET USAGE AND POPULATION STATISTICS
\nJUNE 30, 2015 - Mid-Year Update<\/b><\/span><\/span><\/span><\/p>\n<\/th>\n<\/tr>\n

World Regions<\/b><\/span><\/span><\/span><\/th>\n\n

Population
\n( 2015 Est.)<\/b><\/span><\/span><\/span><\/p>\n<\/th>\n

\n

Internet Users
\nDec. 31, 2000<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

Internet Users
\nLatest Data<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

Penetration
\n(% Population)<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

Users %
\nof Table<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

Growth
\n2000-2015<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

Africa<\/b><\/span><\/span><\/a><\/td>\n\n

1,158,355,663<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

4,514,400<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

313,257,074<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

27.0 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

9.6 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

6,839.1%<\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

Asia<\/b><\/span><\/span><\/a><\/td>\n\n

4,032,466,882<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

114,304,000<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

1,563,208,143<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

38.8 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

47.8 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

1,267.6%<\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

Europe<\/b><\/span><\/span><\/a><\/td>\n\n

821,555,904<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

105,096,093<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

604,122,380<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

73.5 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

18.5 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

474.8%<\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

Middle East<\/b><\/span><\/span><\/a><\/td>\n\n

236,137,235<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

3,284,800<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

115,823,882<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

49.0 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

3.5 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

3,426.1%<\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

North America<\/b><\/span><\/span><\/a><\/td>\n\n

357,172,209<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

108,096,800<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

313,862,863<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

87.9 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

9.6 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

190.4%<\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

Latin America \/ Caribbean<\/b><\/span><\/span><\/a><\/td>\n\n

617,776,105<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

18,068,919<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

333,115,908<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

53.9 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

10.2 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

1,743.6%<\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

Oceania \/ Australia<\/b><\/span><\/span><\/a><\/td>\n\n

37,157,120<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

7,620,480<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

27,100,334<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

72.9 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

0.8 %<\/span><\/span><\/span><\/p>\n<\/td>\n

\n

255.6%<\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

WORLD TOTAL<\/b><\/span><\/span><\/a><\/td>\n\n

7,260,621,118<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

360,985,492<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

3,270,490,584<\/b><\/i><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

45.0 %<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

100.0 %<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n

\n

806.0%<\/b><\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n

\n

NOTES: (1) Internet Usage and World Population Statistics are preliminary for June 30, 2015.<\/span><\/span><\/span><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/th>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/th>\n<\/tr>\n<\/tbody>\n<\/table>\n

Or as a live clock, here:<\/p>\n

https:\/\/www.internetlivestats.com\/internet-users\/<\/a><\/p>\n

\"\"<\/p>\n

Up to this point, the student is usually still interested, as they have a much greater idea of the scale, history and workings of the Internet that they use every day, with a greater appreciation of some of the technical aspects required for its operation.<\/p>\n

I have covered all that as perspective by only introducing 32 bit binary maths and IPV4 number space concepts, at about their most fundamental level that may suffice to give an overall idea of function to the student who asked that seemingly innocent initial question; What is an IP Address?<\/p>\n

If they are still having trouble visualising the massive 32 bit number, and amount of networked computers it represents in theory, the idea can be simplified by constraining the available numbers, one bit at a time, as if the computer was an early pre 1980s model with only a 4 bit memory so it can only hold a maximum number range of 0-15, with which to identify and remember 15 other computers including itself.<\/p>\n

0000 1111 = 0-15 decimal<\/p>\n

Now they should be able to grasp that the more memory a computer has, bit by bit, the more exponential capacity it has to store larger numbers, up to the seemingly massive 4.3 or so billion of a 32 bit memory space.<\/p>\n

If they don't understand this far, you'll know there is little point continuing with any more on the subject without frying both your and their brains, and refer them to more simple topics to study first, and\/or a real world example of 8 bit memory limitations, as in computers circa 1980s:<\/p>\n