Why are the IP addresses separated by dots?

The original programmers of the network modules had no preference when it came to writing your IPV4 address. TCP/IP allows you to write a numeric address using several formats. The following addresses are strictly equivalent:

  • 0x7f000001 – still works, at least on Linux.
  • 0x7f.1 – still works, at least on Linux
  • 0177.00.00.01 – Octal for – Still valid on Linux
  • – Decimal format
  • 2130706433 – Decimal without dot. – Still valid on Linux. Mostly exploited by computer viruses.

Why all this format:

There are several valid forms of digital IPV4 address. Around 1980, the world was separated between octal (DEC, NOVA…) and Hexadecimal (IBM, Amdhal…). TCP/IP was born between these two worlds.

It had a flexible address mode that could adapt to both environments.

The beginning of networks on mini-computers

For the simple reason that the developers didn’t know what we could do with a network, they all started with the development of 255 nodes solution (8 bits address). So TCP/IP, DECNET, ARCNET and many other less known solutions such as “NETWORK” started with computers numbered from 1 to 255. All the protocols of the time used decimal to number the computers which was easier for non computer scientists and researchers.

Definition of Network, Area or similar context.

Before 1983, there were no microcomputers to consider in companies. Moreover, the majority did not own 255 computers. On the other hand, they had an interest to exchange data with other companies.

TCP/IP defined the concept of network class (A,B,C,D,E), DECNET used the concept of Area.host. and “NETWORK” used “Client.Region.Computer”.

At that time, for all addressing formats, the goal was to facilitate the work of routers. It should be remembered that the first dedicated routers from Cisco date from 1985. In 1980, a VAX 11/780 (1 Million$), was a flagship computer of the time. It offered 1 MIPS Drystone of power. A new Raspberry PI 4 of $50 offers 22500 MIPS Drystone. The network protocols were trying to limit the power thirst of the routing algorithms.

Nomenclature with “.”

The “.” was featured in this application. Almost all network protocols used it to stand for Network.Node. In many applications, the “.” denoted a hierarchy. For example, domain names: http://WWW.JYL.CA

(Computer.Domain.Registrar). It replaced the space and gave meaning to the nomenclature.

DECNET with Area→node: 16bits.16bits in octal or decimal.

IPX with Network→Server→Node EX: 0000.0000.0001

But TCP/IP unlike other protocols is much more hierarchical. It relies heavily on the notion of Subnetwork for its routing function. In 1981 or 1982, it already seemed clear that all addresses would ultimately be used when split into Class C, the only realistic way for routing protocols to work as defined in the RFCs.

At that time, some TCP/IP networks used addresses such as: network.node. EX: ping 127.1. or ping 0x7f.1 or ping 0177.01. This type of simple addressing was abandoned with the routing function. We had to use subnets and in 1982 these were called TCP/IP class “C” networks. These were defined by four independent bytes, a type of hierarchy.

Cemented by the introduction of the NCSA MOSAIC browser (1993)

NCSA MOSAIC was written by application/researcher type programmers and less familiar with TCP/IP internals. The first version of the browser only accepted addresses in the form [x.x.x.x] decimal.

For network people this was not really a consideration anymore. There weren’t many programmers who read octal or hexadecimal in the usual way anymore. DNS was working relatively well and this is the 90s.

I believe that this was the marketing basis for the generalization of the X.X.X.X – Decimal format.

DISCLAIMER: Some of the facts stated depend on my perceptions at the time. I have been installing, developing and managing NETWORK and DECNET systems since 1981. However, my first TCP/IP networks were installed in 1984. At that time, the French documentation was non-existent and I didn’t speak English. When I had a question, a translator sent a letter and most of the time, we received a module printout written in “C” with lines highlighted with the Highlighter. This doesn’t help much with the philosophical concepts and whys.

How do I get my son out from under the screens?

I love this question. I am clearly not a reference on the subject of screen intoxication. But I know how to take a step back on this subject and above all I know how to stop.

The first question to ask is: what is he doing on his screens?

You have to know how to find the time-consuming agents and learn how to limit them. The list is almost universal:

  1. First, we find video games, whose objective is to make us waste as much time as possible on them by challenging us to always play more. And sometimes even buy.
  2. In second place come the social networks, which sometimes come first, the fight is hard. It’s hard to resist the constant call of notifications.
  3. Finally, we confuse media and other entertainment like Netflix, YouTube and other happy behemoths.

You have to make choices. I have personally uninstalled most of the toxic applications like Twitter or Facebook, I try to give myself a maximum amount of play time per day, and I put myself in airplane mode as much as possible.

My son is too much on the screens, it has become a 21st century question, an annoyance for the parents, a hobby for the kids… how about getting to know each other?

You don’t know their screens

Take an interest in what he does. Go and see him while he is playing, put a minimum of conviction in it and try to understand the rules a little. In today’s multiplayer games, it is impossible to pause without inevitably losing the game or being penalized by the game. This is obviously very frustrating, so think about it! Set time limits (some games have very long games, so your son will have to adapt) and don’t pop in unexpectedly. The same goes for snap streaks, which require him to send one snap per day (one photo). Let him organize himself as he wants, but set specific times. At 10:30 pm, lights out, you can even set times on the administration settings of some modems. And there, it is impossible to cheat. Try also the “detox” weeks for example when you go on vacation.

Something in return

It’s all very well to turn off the screens. But what is he doing without? The thought of having to cut out his favorite TV show to study for exams is not motivating and don’t try to get him to install digital revision programs: it doesn’t work very well and it’s not effective. He can go out, meet friends, in short go outside.

But what do you suggest? I’m not a social worker, but the prospect of recommending to parents that they cut the wires and put their children outside disgusts me to no end. If you have some time to spare, be with him! Go to games, concerts, crafts, and sometimes even play with him (I’m told in my ear that doesn’t answer the question). Plug in the books too, reading is my second favorite activity (after learning) and there is something for everyone. Go on hikes, go to exhibitions…show him how beautiful the world is without pixels, your child will never go alone or he won’t want to, so do it with him!

How do I fix the black screen on my PC?

If while working on your PC, the screen suddenly goes black, don’t panic! The solution is right here.

Black screens are caused by various things.

*You have installed applications that you do not know and you have not uninstalled them.

*After an update

*While surfing on NNe, you have visited unsecured sites.


Enough talk, here is how to fix your PC:

Always have a reflex of restarting your PC( by pressing the power button for a few seconds), it can fix everything. Otherwise, when you start your PC, press the f8 key.

There, the screen gives you several choices.

“Start Windows in Safe Mode” is a solution.
If you are allowed to do this, you must

  • access your control panel (“Start”, then “Control Panel”)
  • then select “Backup and Restore”
  • “Restore system settings or your computer”
  • There you will have the opportunity to restore your computer
  • The latter restarts and carries out the restoration.

Sometimes, the safe mode is not proposed, it is “System Restart” that is proposed instead.
Choose this option and let yourself be guided, you will not lose your data in any case, your operating system will simply return to a previous version at the system level which will correct the errors generated in the meantime.

Also, a simple restart of your computer is sometimes able to correct the problems related to a black screen.

System reinstallation

In the worst case,

insert your Operating System installation CD/DVD in your CD/DVD drive or on a USB key.

Start your computer by pressing the F2 key to access the BIOS, go to the “BOOT” tab

and choose the boot on CD/DVD drive.

Your computer will then reinstall your operating system.
To keep your data, choose the upgrade and not the reinstallation of the system, they will then be accessible in a folder named Windows.old located in your hard disk.

In case of a black screen, don’t panic, the solution exists, follow these instructions and restore your computer. If you are not confident enough, call the PC repairman.

Why does my computer turn on so slowly?

There are several explanations.

The hardware obviously plays a role.
Your computer may not perform “naturally”. The components that make it up make it not fast, the speed at which it processes data is low. If it is a fixed one, you can eventually change some components. It seems to me that it is the processor and the RAM that are involved in this work.
SSDs are known to be fast as well.

There is a software part.
The more programs you have running at startup, the longer it takes for the computer to turn on. Don’t hesitate to prohibit programs from launching at startup if they are not needed right from the start (a word processor doesn’t need to load at startup, it can wait to be requested without any problem for example).
For Windows 10, just search for “startup” and the computer will suggest “startup applications” which will open a settings page. There you can disable unnecessary programs. Be careful not to disable all those you do not know, some are necessary (mouse, keyboard, sound, graphics etc.). Only deactivate programs that you know and are sure that they will not create problems if they are deactivated.

Memory can also affect boot speed.
The fuller the computer’s hard drive is, the longer it may take to boot up and launch applications, especially if it is not defragmented regularly. The computer will look for information where it is on its disk(s), so if it needs some information on one side and the rest on another, it will take a little time to go and find it.

Malware can be a factor.
Some viruses or Trojan horses are known to slow down computers. So always keep an active anti-virus program up to date. Remember to scan regularly and be careful when downloading anything.

Computers are slower when they are hot! The components should not exceed a certain temperature. So when it’s hot, the computer is deliberately putting less strain on its components to avoid overheating. Think of dusting it once a year at least at the level of the fans (if it is a fixed one, you can even open it to dust delicately inside). There are dedicated dry compressed air cans. If you have a laptop that heats up, there are fans created specifically for them.
Also check with professionals to change the thermal paste regularly.

It is probably a machine running Windows.

At the time I was at work, the norm was to reinstall Windows every year, because the performance was going down with time. But I admit that it was not yet Windows 10.

Try to see if there are any Linux groups in your city/neighborhood/school, and try the performance of your machine by booting on a Linux USB key.

How to fix a computer that turns on but does not start Windows 10?

Beware of the EFI boot that is sometimes damaged, or after an update of the system, it is necessary to launch windows in repair mode and repair this boot (unfortunately you need to know a little about the subject).

Repairing an EFI boot loader on a GPT hard drive for Windows 7, 8, 8.1 and 10 on your Dell desktop computer

If, at boot time (after reboot), some keys (related to the brand/version of your Windows and your PC like ECHAP/SUPPRIM/F2,F8,F9,F10,F12) do not allow to boot Windows in repair mode and restore the operating system “without erasing data”, You need to make a bootable USB key or an external repair disk with another PC. A version of Windows 10 USB to reinstall your PC is available for free on the Microsoft website or on the website of the brand of your computer (windows OEM version). Use USBIT to make your key from the downloaded image. Then boot on this key in order to repair or reinstall Windows without deleting data (if the hard disk is not broken, otherwise same procedure but after replacing your hard disk by a new one, preferably a 256Gb, 512Gb or better 1Tb SSD disk).

All the procedures for booting into safe mode and repairing and restoring and downloading images of Windows are available on the Microsoft site and other computer experts.

Indeed, it is quite vague. Are you able to boot with an installation key, for example, of Linux, or of WIndow, made on another computer? Are you able to access the configuration screen for disks, memory, boot, etc (also known as BIOS)? Do you have an error number displayed on the screen?

If you can boot from a USB stick, are you able to see your hard drives that you know are in your computer?

To me, the two most likely things are:

  • A defective hard drive
  • An installation of Windows that has gone haywire

In both cases, you should be able to boot from a USB stick (or CDROM) with something like a Windows installation key – or even better: Linux.

I have often rescued failed hard drives by booting with Linux because Windows didn’t work anymore.

There are too many possibilities to take into account. That it lights up, it’s not bad.

Start by looking if the hard disk light turns on at startup. If not, you should check the BIOS, to see if it recognizes the hard disk (or SSD). In any case, it would be good to check the BIOS settings, to see that everything is in order. If it doesn’t recognize it, then you have to look for the reason.

If you have excluded these errors, then you should check the installation of Windows 10 and/or check the “health” of the disk. If it is not working, then you have to change it.

It is also possible that there is a problem with the integrity of Windows 10 files. For example, the Boot sector has jumped. Then you should reinstall, or repair with a Windows 10 installation support.

If you don’t know how to do this, get help.