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https://github.com/jotavare/net_practice
Networking exercises with a focus on IP addresses and subnet masks.
https://github.com/jotavare/net_practice
ip ipcalc ipv4 network router routing subnet subnets tcp
Last synced: 6 days ago
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Networking exercises with a focus on IP addresses and subnet masks.
- Host: GitHub
- URL: https://github.com/jotavare/net_practice
- Owner: jotavare
- License: mit
- Created: 2023-07-15T02:57:05.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2024-06-26T23:32:10.000Z (5 months ago)
- Last Synced: 2024-06-27T03:02:19.011Z (5 months ago)
- Topics: ip, ipcalc, ipv4, network, router, routing, subnet, subnets, tcp
- Language: JavaScript
- Homepage:
- Size: 2.14 MB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
About •
How to use •
Practice and Evaluation •
Subnet •
Contributing •
License
## ABOUT
This is a practical networking exercise aimed at exploring the fundamentals of networking. In this project, I configured a small-scale network and delved into the world of TCP/IP addressing. The goal is to complete 10 levels, each designed to challenge and enhance my networking knowledge.
- [Subject](https://github.com/jotavare/netpractice/blob/main/subject/en_subject_netpractice.pdf) `PDF`
- [References](https://github.com/jotavare/42-resources#04-netpractice) `GitHub`
## HOW TO USE
#### 1º - Change directory
```bash
cd netpractice/netpractice/exercises/
```
#### 2º - Open the index.html file
> It doesn't work well in Firefox.
```bash
open -a "Google Chrome" index.html
```
## PRACTICE AND EVALUATION
#### UTILITY
> This utility will help us understand more about Address Manipulation:
```
brew install ipcalc
ipcalc 172.30.0.69/30
```
#### COMPLETE ALL 10 LEVELS
> There will be a practice and evaluation mode:
- `Practice mode` - Insert your 42 intra username. You will do all 10 levels.
- `Evaluation mode` - 3 random levels from level 6 to level 10. You only have 15 minutes for all.
> [!WARNING]
> Before moving to the next level, don’t forget to export your configuration using the `Get My Config` button so you can put it in your Git repository.
#### BUTTONS
> There will be 2 buttons on the top left corner (3 if you completed a level):
- `Check again` - Verify whether your configuration was correct or not.
- `Get my config` - Download your configuration. It will be needed to turn in your assignment.
- `Next level` - Click on this button to get to the next level.
## SUBNET
> A **subnet or subnetwork** is a *network inside a network*. Subnets make networks more efficient.
**Subnetting** is the process of stealing bits from the HOST part of an IP address to divide the large network into smaller ones called subnets. After subnetting, we end up with **NETWORK SUBNET HOST** fields, and we always reserve an IP address to *identify the subnet* and another one to *identify the broadcast subnet address*, and through subnetting, network traffic can travel a shorter distance without passing through unnecessary routes to reach its destination.
#### CALCULATE SUBNET MASK FROM IP ADDRESS
> 1º - Find Subnet Number (we are gonna use the IP address `10.20.4.13/29` for this example):
```
Subtract prefix number from /32
32 - 29 = 3
Calculate Subnet Mask:
8 bits - 3 bits = 5 bits (Network bits turned on)
You might be asking why 8 bits, 8 bits are required for each octet.
|-------|-------|-------|-------|-------|-------|-------|-------|
| 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 |
|-------|-------|-------|-------|-------|-------|-------|-------|
| 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 |
|-------|-------|-------|-------|-------|-------|-------|-------|
| 128 + | 64 + | 32 + | 16 + | 8 | = 248 |
|-------|-------|-------|-------|-------|-------|-------|-------|
Subnet Mask = 255.255.255.248
```
> 2º - Find Subnet Size:
```
Raise 2 to the power of deduction (8 - 3 = 5) -> Let's call it n.
2 ** n = Subnet Size.
2 ** 3 = Subnet Sizes for each subnet.
2 * 2 * 2 = 8
NOTE: 8 is the block size for the subnet, so for example:
the increments will now be 0 8 16 24 32 and so on (we add 8 each time)
```
> 3º - Find Broadcast Address:
```
Subnet size - 1
(2 ** n) - 1 = Broadcast Address
(2 ** 3) - 1 = (8 - 1) = 7
```
> 4º - Locate IP Address Subnet:
```
Identify subnet block for IP address:
-> Where in each increment is the address 10.20.4.13/29 located (0 8 16 32 40)?
13 falls between 8 and 16 and therefore the address is in the valid host range of the subnet 10.20.4.8/29
```
> 5º - Calculate The Valid Hosts:
```
Subnet size - 2
(2 ** n) - 2 = Valid Host Range
(2 ** 3) - 2 = (8 - 2) = 6
```
> And from these steps, we can know 4 important things:
```
Subnet Address -> 10.20.4.8/29
Min Host Address -> 10.20.4.9/29
Max Host Address -> 10.20.4.14/29
Broadcast Address -> 10.20.4.15/29
```
#### SUBNET MASK TABLE
> Here is a quick reference table for help when subnetting.
|Subnet Mask |CIDR | Binary Notation |Network Bits |Host Bits | Available Addresses |
| - | - | - | - | - | - |
|255.255.255.255| /32| 11111111.11111111.11111111.11111111| 32| 0 | 1 |
|255.255.255.254| /31| 11111111.11111111.11111111.11111110| 31| 1 | 2 |
|255.255.255.252| /30| 11111111.11111111.11111111.11111100| 30| 2 | 4 |
|255.255.255.248| /29| 11111111.11111111.11111111.11111000| 29| 3 | 8 |
|255.255.255.240| /28| 11111111.11111111.11111111.11110000| 28| 4 | 16 |
|255.255.255.224| /27| 11111111.11111111.11111111.11100000| 27| 5 | 32 |
|255.255.255.192| /26| 11111111.11111111.11111111.11000000| 26| 6 | 64 |
|255.255.255.128| /25| 11111111.11111111.11111111.10000000| 25| 7 | 128 |
|255.255.255.0 | /24| 11111111.11111111.11111111.00000000| 24| 8 | 256 |
|255.255.254.0 | /23| 11111111.11111111.11111110.00000000| 23| 9 | 512 |
|255.255.252.0 | /22| 11111111.11111111.11111100.00000000| 22| 10| 1024 |
|255.255.248.0 | /21| 11111111.11111111.11111000.00000000| 21| 11| 2048 |
|255.255.240.0 | /20| 11111111.11111111.11110000.00000000| 20| 12| 4096 |
|255.255.224.0 | /19| 11111111.11111111.11100000.00000000| 19| 13| 8192 |
|255.255.192.0 | /18| 11111111.11111111.11000000.00000000| 18| 14| 16384 |
|255.255.128.0 | /17| 11111111.11111111.10000000.00000000| 17| 15| 32768 |
|255.255.0.0 | /16| 11111111.11111111.00000000.00000000| 16| 16| 65536 |
|255.254.0.0 | /15| 11111111.11111110.00000000.00000000| 15| 17| 131072 |
|255.252.0.0 | /14| 11111111.11111100.00000000.00000000| 14| 18| 262144 |
|255.248.0.0 | /13| 11111111.11111000.00000000.00000000| 13| 19| 524288 |
|255.240.0.0 | /12| 11111111.11110000.00000000.00000000| 12| 20| 1048576 |
|255.224.0.0 | /11| 11111111.11100000.00000000.00000000| 11| 21| 2097152 |
|255.192.0.0 | /10| 11111111.11000000.00000000.00000000| 10| 22| 4194304 |
|255.128.0.0 | /9 | 11111111.10000000.00000000.00000000| 9 | 23| 8388608 |
|255.0.0.0 | /8 | 11111111.00000000.00000000.00000000| 8 | 24| 16777216|
## CONTRIBUTING
If you find any issues or have suggestions for improvements, feel free to fork the repository and open an issue or submit a pull request.
## LICENSE
This project is available under the MIT License. For further details, please refer to the [LICENSE](https://github.com/jotavare/net_practice/blob/master/LICENSE) file.