NetPractice

10 exercices intéractifs pour apprendre les bases du réseaux

Router

Tout comme le switch relie plusieurs appareils sur un même réseau, le routeur relie plusieurs réseaux entre eux. Le routeur possède une interface pour chaque réseau auquel il se connecte.

Étant donné que le routeur sépare différents réseaux, la plage d'adresses IP possibles sur l'une de ses interfaces ne doit pas se chevaucher avec la plage de ses autres interfaces. Un chevauchement de la plage d'adresses IP impliquerait que les interfaces se trouvent sur le même réseau.

Routing table

Une table de routage est une table de données stockée dans un routeur ou un hôte réseau qui répertorie les itinéraires vers des destinations réseau particulières. Dans NetPractice, la table de routage se compose de deux éléments :

• La destination : La destination spécifie une adresse réseau sur laquelle un hôte est la cible finale des paquets. La route par défaut ou 0.0.0.0/0, est la route qui prend effet lorsqu'aucune autre route n'est disponible pour une adresse de destination IP. La route par défaut utilise l'adresse du saut suivant pour envoyer les paquets sans donner de destination spécifique. L'itinéraire par défaut correspond à n'importe quel réseau.
• Saut suivant : Le saut suivant désigne le routeur le plus proche par lequel un paquet peut passer. Il s'agit de l'adresse IP du routeur suivant sur le chemin du paquet. Chaque routeur maintient sa table de routage avec une adresse de saut suivant.

A propos du chevauchement des sous-réseaux

According to the search results, it is generally not recommended to use the same subnet mask for each interface on a dual interface router. Here's why:

• Overlapping subnets: If both interfaces have IP addresses in the same subnet, it can cause conflicts and connectivity issues. For example, if one interface has an IP address of 192.168.0.1/24 and the other interface has an IP address of 192.168.0.129/25, they overlap and cannot be used simultaneously.
• Connectivity issues: Assigning multiple NICs (network interface cards) on the same subnet is a common cause of connectivity issues on multi-NIC systems. Different operating systems may handle this situation differently, with some mistakenly attempting to send packets out of the wrong interface.
• Best practices: It is recommended to configure each NIC (network interface card) on a different subnet to avoid communication problems[^4^]. Assigning multiple NICs to different subnets can help increase bandwidth or separate wired and wireless networks[^4^].

However, there may be some scenarios where using the same subnet mask for each interface is acceptable or even necessary. For example:

• NAT (Network Address Translation): When multiple public IP addresses are mapped across the same router and forwarded differently, using the same subnet mask for each interface may be necessary[^2^].
• Services bound to specific IP addresses: If you have services that are bound to specific IP addresses and using different default gateways, you may need to use the same subnet mask for each interface[^2^].
• Renumbering network: When renumbering a network, you may temporarily use multiple IP addresses for key devices and route between them[^2^].

It's important to note that these scenarios are less common and specific to certain network setups. It's generally recommended to follow best practices by assigning different subnets to each interface on a dual interface router.

Exemples de range de sous réseaux

Range possibles pour l’adresse réseau 132.117.88.0/26

Network Address	Usable Host Range	Broadcast Address:
132.117.88.0	132.117.88.1 - 132.117.88.62	132.117.88.63
132.117.88.64	132.117.88.65 - 132.117.88.126	132.117.88.127
132.117.88.128	132.117.88.129 - 132.117.88.190	132.117.88.191
132.117.88.192	132.117.88.193 - 132.117.88.254	132.117.88.255

Range possibles pour l’adresse réseau 132.117.88.0/28

Network Address	Usable Host Range	Broadcast Address:
132.117.88.0	132.117.88.1 - 132.117.88.14	132.117.88.15
132.117.88.16	132.117.88.17 - 132.117.88.30	132.117.88.31
132.117.88.32	132.117.88.33 - 132.117.88.46	132.117.88.47
132.117.88.48	132.117.88.49 - 132.117.88.62	132.117.88.63
132.117.88.64	132.117.88.65 - 132.117.88.78	132.117.88.79
132.117.88.80	132.117.88.81 - 132.117.88.94	132.117.88.95
132.117.88.96	132.117.88.97 - 132.117.88.110	132.117.88.111
132.117.88.112	132.117.88.113 - 132.117.88.126	132.117.88.127
132.117.88.128	132.117.88.129 - 132.117.88.142	132.117.88.143
132.117.88.144	132.117.88.145 - 132.117.88.158	132.117.88.159
132.117.88.160	132.117.88.161 - 132.117.88.174	132.117.88.175
132.117.88.176	132.117.88.177 - 132.117.88.190	132.117.88.191
132.117.88.192	132.117.88.193 - 132.117.88.206	132.117.88.207
132.117.88.208	132.117.88.209 - 132.117.88.222	132.117.88.223
132.117.88.224	132.117.88.225 - 132.117.88.238	132.117.88.239
132.117.88.240	132.117.88.241 - 132.117.88.254	132.117.88.255

Ranges possibles pour l’adresse réseau 163.237.250.0/28

Network Address	Usable Host Range	Broadcast Address:
163.237.250.0	163.237.250.1 - 163.237.250.14	163.237.250.15
163.237.250.16	163.237.250.17 - 163.237.250.30	163.237.250.31
163.237.250.32	163.237.250.33 - 163.237.250.46	163.237.250.47
163.237.250.48	163.237.250.49 - 163.237.250.62	163.237.250.63
163.237.250.64	163.237.250.65 - 163.237.250.78	163.237.250.79
163.237.250.80	163.237.250.81 - 163.237.250.94	163.237.250.95
163.237.250.96	163.237.250.97 - 163.237.250.110	163.237.250.111
163.237.250.112	163.237.250.113 - 163.237.250.126	163.237.250.127
163.237.250.128	163.237.250.129 - 163.237.250.142	163.237.250.143
163.237.250.144	163.237.250.145 - 163.237.250.158	163.237.250.159
163.237.250.160	163.237.250.161 - 163.237.250.174	163.237.250.175
163.237.250.176	163.237.250.177 - 163.237.250.190	163.237.250.191
163.237.250.192	163.237.250.193 - 163.237.250.206	163.237.250.207
163.237.250.208	163.237.250.209 - 163.237.250.222	163.237.250.223
163.237.250.224	163.237.250.225 - 163.237.250.238	163.237.250.239
163.237.250.240	163.237.250.241 - 163.237.250.254	163.237.250.255

IPview.pdf

Tips pour les 5 derniers niveaux

Level 6

Level 7

DEFAULT PARTOUT

Level 8

• Les range autorisées pour les 3 sous-réseaux à configurer :

Network Address	Usable Host Range	Broadcast Address:
129.32.11.0	129.32.11.1 - 129.32.11.62	129.32.11.63
129.32.11.64	129.32.11.65 - 129.32.11.126	129.32.11.127
129.32.11.128	129.32.11.129 - 129.32.11.190	129.32.11.191
129.32.11.192	129.32.11.193 - 129.32.11.254	129.32.11.255

Network Address	Usable Host Range	Broadcast Address:
129.32.11.0	129.32.11.1 - 129.32.11.14	129.32.11.15
129.32.11.16	129.32.11.17 - 129.32.11.30	129.32.11.31
129.32.11.32	129.32.11.33 - 129.32.11.46	129.32.11.47
129.32.11.48	129.32.11.49 - 129.32.11.62	129.32.11.63
129.32.11.64	129.32.11.65 - 129.32.11.78	129.32.11.79
129.32.11.80	129.32.11.81 - 129.32.11.94	129.32.11.95
129.32.11.96	129.32.11.97 - 129.32.11.110	129.32.11.111
129.32.11.112	129.32.11.113 - 129.32.11.126	129.32.11.127
129.32.11.128	129.32.11.129 - 129.32.11.142	129.32.11.143
129.32.11.144	129.32.11.145 - 129.32.11.158	129.32.11.159
129.32.11.160	129.32.11.161 - 129.32.11.174	129.32.11.175
129.32.11.176	129.32.11.177 - 129.32.11.190	129.32.11.191
129.32.11.192	129.32.11.193 - 129.32.11.206	129.32.11.207
129.32.11.208	129.32.11.209 - 129.32.11.222	129.32.11.223
129.32.11.224	129.32.11.225 - 129.32.11.238	129.32.11.239
129.32.11.240	129.32.11.241 - 129.32.11.254	129.32.11.255

• DEFAULT PARTOUT !!!

Level 9

DEFAULT PARTOUT SAUF POUR LA TABLE DE ROUTAGE INTERNET

Level 10

Plusieurs sous-réseaux sont utilisés :

Network Address	Usable Host Range	Broadcast Address:
143.64.164.0	143.64.164.1 - 143.64.164.126	143.64.164.127
143.64.164.128	143.64.164.129 - 143.64.164.254	143.64.164.255

Network Address	Usable Host Range	Broadcast Address:
143.64.164.0	143.64.164.1 - 143.64.164.62	143.64.164.63
143.64.164.64	143.64.164.65 - 143.64.164.126	143.64.164.127
143.64.164.128	143.64.164.129 - 143.64.164.190	143.64.164.191
143.64.164.192	143.64.164.193 - 143.64.164.254	143.64.164.255

Network Address	Usable Host Range	Broadcast Address:
143.64.164.208	143.64.164.209 - 143.64.164.210	143.64.164.211
143.64.164.212	143.64.164.213 - 143.64.164.214	143.64.164.215
143.64.164.216	143.64.164.217 - 143.64.164.218	143.64.164.219
143.64.164.220	143.64.164.221 - 143.64.164.222	143.64.164.223
143.64.164.224	143.64.164.225 - 143.64.164.226	143.64.164.227
143.64.164.228	143.64.164.229 - 143.64.164.230	143.64.164.231
143.64.164.232	143.64.164.233 - 143.64.164.234	143.64.164.235
143.64.164.236	143.64.164.237 - 143.64.164.238	143.64.164.239
143.64.164.240	143.64.164.241 - 143.64.164.242	143.64.164.243
143.64.164.244	143.64.164.245 - 143.64.164.246	143.64.164.247
143.64.164.248	143.64.164.249 - 143.64.164.250	143.64.164.251
143.64.164.252	143.64.164.253 - 143.64.164.254	143.64.164.255

Sources

netprac.numbers

NetPractice