Routers: how does it work and which model to choose?

In the 21st century, there is a tendency to erroneously classify in the "router" category any box connected live on the Net (typically the "Internet boxes", but not only). Yet, from a technical point of view, it's much more than that. We will try to separate the towels and towels to better navigate.

As we have discovered in the IPv6 folder , the Internet is composed of routers that play hot potato with your IPv4 packets full of your precious data. And this little game, they are rather effective and usually manage to direct the good potato to the right person, that is to say the computer to which the package is intended.

  • This package is marked "for Caffeine", I do not know the way to his machine, hop I take the path by default
  • This package is marked "for Faskil", I know the road that goes well to his machine, en route!

And a router, that's just that. Only that. All the time.

Clearly, the router only transmits data packets from one point to another, without being interested in their content. Suddenly, it's ultimately stupid and that's why we regularly say that in the structure of the Internet, it is not the trunk of the network that provides the intelligence, it is the leaves.

And the Internet box was ...

Even if one tends to qualify any Internet router box, it is actually closer to a firewall than a simple router, a firewall is de facto a router, but with more intelligence. To really understand the difference between the two, just remember this: the router is only concerned with the destination address where to send the data packet, where the firewall will take a closer look at the packet and get a feel for it. few more questions about it. Enterprise routers are basic product for any business/enterprise.

 

  • Who is the sender? Depending on the sender, we can accept or reject the package.
  • Who is the recipient? In the same way as for the sender, we can accept or refuse the package depending on the recipient.
  • What is the application (the port, in technical terms) that is used? You can also block access to certain applications (ports) such as the web server (port 80).

And of course, we can also use combinations of these conditions:

  • If it comes from Faskil and it must go to Caffeine HTTP (port 80), accept.
  • If it comes from Mr. Pirate and it must go to Caffeine HTTP (port 80), refuse.

It looks pretty simple like that, except that we are quickly confronted with a little problem: we do not really know how to identify Faskil and Mr. Pirate in the story, they will just be IP addresses. If we know Faskil, and if his ISP provides him a fixed IP, we can reasonably write the rule 1. On the other hand, as we do not know the IP of Mr. Pirate (and it's a little complicated to ask him) , we will have trouble writing rule 2. The scope of a firewall is limited to IP protocols, which is certainly a bit limited, but still allows to do a lot of things.

In addition, all firewalls (to my knowledge) are able to do NAT , as seen in the IPv6 folder. They can therefore match a single public external address visible on the Internet to all the addresses of a private network. On the other hand, a simple router can not.

Suddenly, an Internet box and routers consumer is what?

Whatever your ISP, an Internet box is a firewall, although very basic, but a firewall despite everything. In the same way, any Wi-Fi "router" is also a firewall. Be careful not to confuse what marketing calls "Wi-Fi router" and "Wi-Fi access point", it's not the same thing. The commercial Wi-Fi router is actually a firewall, quite similar in its features with an Internet box. Access points are much more basic, and if they sometimes offer a DHCP server, they rarely integrate a firewall, even simple.

The term "Wi-Fi router" is, as I pointed out at the beginning of the file, an abuse of language. To be correct, we should rather talk about firewall / Wi-Fi router. Yes, I pinch if I want.

Box FAI or "router / firewall" of the trade, it is necessary to choose

For 90% of users, the features offered by the Internet box provided by ISPs will suffice. But we are on Geekzone, and "power users" requires, these devices will not necessarily be enough for our advanced uses. The recurring problem of these devices is an area of ​​reception Wi-Fi at best average, or using outdated standards. It evolves , but slowly, and the duration of exploitation of these products makes the return of the problem inevitable in the medium term.

The other potential concern comes from the absence of advanced firewalling options, or simply an old network switch (blocked at 10 / 100MB instead of gigabit), which can play a great deal on the speed of transfer of video. tata Janine in 1080p DTS on your network. Let's take a look at the solutions that exist on the market ...

Wi-Fi turbo boost

There are several ways to improve or replace Wi-Fi in a box.

1. The Wi-Fi repeater

This solution is the simplest to implement in terms of structural needs, but it is unfortunately not necessarily the most effective. Indeed, the repeater connects to your box in Wi-Fi to provide you with a more effective signal. It is imperative that this repeater is placed in the Wi-Fi zone of influence of the box in question, but not too close because it is a little stupid, but not too far either because it will not work ...

The example above is very telling: the repeater is placed at the blue zone limit, so with a weak reference signal. The "repetition" of the signal will not be really optimal.

The other important point to watch with this kind of devices is the choice of the Wi-Fi channel. You should know that the 2.4 GHz band offers a choice of 14 channels, and it is obviously better not to cross the streams. : if all the Wi-Fi kiosks are on channel 2, it's obviously going to work less well.

Unfortunately, it is not always possible to modify this channel on the boxes of our ISPs. And sometimes, the repeater (especially if it is cheap) does not propose it either. So choose a repeater that offers this option, and use a tool (like Wifi Analyzer on Android) to list the channels already used in your home. Once these valuable information is in hand, make some adjustments:

  • if your box is on channel 2, set the repeater on channel 8 (far, what)
  • if your neighbors are equipped with Wi-Fi too, try using a relatively free channel

This will limit the case, but your connection will be very dependent on the quality of the Wi-Fi connection between the box and the repeater (spoiler alert: in general, it does not work very well, unless you directly attach the repeater to the box).

Price: between 20 and 40 euros, some models offering in addition to recover if necessary the network via an Ethernet cable, similar to what we will see in the next point.