reecriture de subnetting part 3

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# Subnetting (Part 3 - VLSM) # Subnetting (Part 3 - VLSM)
## Class B Reference Table
class B Refference table
| Prefix | Subnets | Hosts | | Prefix | Subnets | Hosts |
| ------ | ------- | ----- | |--------|---------|-------|
| /17 | 2 | 32766 | | /17 | 2 | 32766 |
| /18 | 4 | 16382 | | /18 | 4 | 16382 |
| /19 | 8 | 8190 | | /19 | 8 | 8190 |
@@ -23,10 +22,10 @@ class B Refference table
--- ---
class C Refference table ## Class C Reference Table
| Prefix | Subnets | Hosts | | Prefix | Subnets | Hosts |
| ------ | ------- | ----- | |--------|---------|-------|
| /25 | 2 | 126 | | /25 | 2 | 126 |
| /26 | 4 | 62 | | /26 | 4 | 62 |
| /27 | 8 | 30 | | /27 | 8 | 30 |
@@ -34,134 +33,129 @@ class C Refference table
| /29 | 32 | 6 | | /29 | 32 | 6 |
| /30 | 64 | 2 | | /30 | 64 | 2 |
| /31 | | (0) | | /31 | | (0) |
| /32 | | (0)-2 | | /32 | | (02) |
## QUIZ Question 1 ---
You have been given the 172.30.0.0/16. your company requires ## Quiz Question 1
100 subnets with at least 500 hosts per subnet. What prefix
length should you use?
I should use 172.168.0.0/23 You have been given the network **172.30.0.0/16**. Your company requires
because it compatible with 100 subnet and 500 hosts **100 subnets with at least 500 hosts per subnet**.
subnet mask -> 255.255.254.0 **Answer:**
- Prefix: `/23`
- Network: `172.30.0.0/23`
- Subnet mask: `255.255.254.0`
---
## Quiz Question 2 ## Quiz Question 2
What subnet does host 172.21.111.201/20 belong to ? What subnet does host **172.21.111.201/20** belong to?
10101100.00010101.*0110*1111.11001001 ```
172.21.111.201
10101100.00010101.*0110*0000.00000000
172.21.96.0
## Quiz question 3 10101100.00010101.01101111.11001001 (IP)
10101100.00010101.01100000.00000000 (Network)
What is the broadcast address of the network 192.168.91.78/26 ```
11000000.10101000.10110011.*01*001110 **Answer:** `172.21.96.0/20`
192.168.91.78
11000000.10101000.10110011.*01*111111
192.168.91.127
## Quiz question 4 ---
You divide the 172.16.0.0/16 network into 4 subnets of equal size. ## Quiz Question 3
Identify the network and broadcast addresses of the second subnet
Subnet 1 : What is the broadcast address of the network **192.168.91.78/26**?
Network address
172.16.0.0/18
10101100.00011010.*00*000000.00000000
broadcast:
172.16.0.0/18
10101100.00011010.*00*111111.00000000
172.16.63.255/18
Subnet 2 : ```
Network address
172.16.64.0/18
10101100.00011010.*01*000000.00000000
broadcast:
172.16.65.0/18
10101100.00011010.*01*111111.00000000
172.16.127.255/18
Subnet 3 : 11000000.10101000.10110011.01001110 (IP)
Network address 11000000.10101000.10110011.01111111 (Broadcast)
172.16.128.0/18
10101100.00011010.*10*000000.00000000
broadcast:
172.16.128.0/18
10101100.00011010.*10*111111.00000000
172.16.191.255/18
Subnet 4 : ```
Network address
172.16.192.0/18
10101100.00011010.*11*000000.00000000
broadcast:
172.16.192.0
10101100.00011010.*11*111111.00000000
172.16.255.255/18
## Quiz question 5 **Answer:** `192.168.91.127`
You divide the 172.30.0.0/16 network into subnets of 1000 hosts each. How many subnets ---
are you able to make
I'm able to make 64 subnets ## Quiz Question 4
## Subentting class A Networks You divide the **172.16.0.0/16** network into 4 equal subnets.
Identify the network and broadcast addresses.
The process of subnetting Class A, Class B and Class C networks is Exactly the same ! ### Subnet 1
- Network: `172.16.0.0/18`
- Broadcast: `172.16.63.255`
### Example 2 ### Subnet 2
- Network: `172.16.64.0/18`
- Broadcast: `172.16.127.255`
You hace been given the 10.0.0.0/8 network. You must create 2000 subnets which ### Subnet 3
will be distributed to various enterprises. - Network: `172.16.128.0/18`
What prefix length must you use ? - Broadcast: `172.16.191.255`
How many host addresses usable addresses will be in each subnet?
10.0.0.0 ### Subnet 4
00001010.00000000.0000000.0000000 - Network: `172.16.192.0/18`
2, 4, 8, 16,32, 64,128,256, 512, 1024, 2048 - Broadcast: `172.16.255.255`
00001010.*00000000.000*00000.0000000
Answer: ---
10.0.0.0/19
8192 - 2 = 8190 hosts
### Example 2 ## Quiz Question 5
PC1 has an IP address of 10.217.182.223/11. You divide the **172.30.0.0/16** network into subnets of **1000 hosts each**.
Identify the following for PC1's subnet: **Answer:** 64 subnets
1) Network address:10.192.0.0/11
2) Broadcast address: 10.223.255.255
3) First usable address: 10.192.0.1
3) Last usable address:10.223.255.254
3) Nuber of host (usable) address: 2,097,150
10.217.182.223 ---
00001010.*110*11001.10110110.11011111
## [[VLSM]] ## Subnetting Class A Networks
Variable-Length Subnet Masks The process of subnetting Class A, B, and C networks is exactly the same.
- Until now, we have practiced subentting used FLSM (Fixed-Length Subnet Masks). ---
- This means that all of the subents use the same prefix length (ie. subnetting a class C
into 4 subenets using /26).
- VLSM (Variable-Length Subnet Masks) is the process of creating subnets of different sizes
to make your use of network addresses more eficient
- VLSM is more complicated than FLSM, but it's easy if you folow the steps correctly.
### Exaple 1 ## Example 1
We must divide 192.168.1.0/24 must divided between 5 subnets You are given the network **10.0.0.0/8**.
You must create **2000 subnets**.
### Solution
**Answer:**
- Prefix: `/19`
- Usable hosts: `8192 - 2 = 8190`
---
## Example 2
PC1 has IP address **10.217.182.223/11**
### Subnet Details
- Network: `10.192.0.0/11`
- Broadcast: `10.223.255.255`
- First usable: `10.192.0.1`
- Last usable: `10.223.255.254`
- Usable hosts: `2,097,150`
---
## VLSM (Variable-Length Subnet Masks)
- Previously, we used **FLSM (Fixed-Length Subnet Masks)**
- All subnets had the same prefix length
- VLSM allows **different subnet sizes** for better efficiency
- More flexible, slightly more complex
---
## Example (VLSM Design)
```
Tokyo Lan A = 110 Hosts --- Tokyo Lan B = 8 Hosts Tokyo Lan A = 110 Hosts --- Tokyo Lan B = 8 Hosts
| |
Router Router
@@ -169,61 +163,72 @@ We must divide 192.168.1.0/24 must divided between 5 subnets
Router Router
| |
Toronto Lan A = 29 Hosts --- Toronto Lan B = 45 Hosts Toronto Lan A = 29 Hosts --- Toronto Lan B = 45 Hosts
```
#### VLSM Steps We must divide **192.168.1.0/24** into 5 subnets:
1) Assign the largest subnet at the start of the address space. - Tokyo LAN A → 110 hosts
2) Assign the second- largest subnet after it. - Tokyo LAN B → 8 hosts
3) Repeat the process until all subnets have been assigned - Toronto LAN A → 29 hosts
- Toronto LAN B → 45 hosts
- Point-to-point link
we will do this in this order ### Steps
Tokyo LAN A -> Toronto LAN B -> Toronto LAN A -> Tokyo LAN B -> Point to point 1. Assign largest subnet first
2. Continue in descending order
3. Repeat until done
##### Tokyo LAN A ### Allocation Order
Network address: 192.168.1.0/25 Tokyo A → Toronto B → Toronto A → Tokyo B → Point-to-point
Broadcast address: 192.168.1.127/25
First usable address: 192.168.1.1/25
Last usable address: 192.168.1.126/25
Total Number of usable host address: 126
##### Toronto LAN B ---
if we add 1 to the Tokyo Broadcast address we get the next Network address
Network address: 192.168.1.128/26 ### Tokyo LAN A
Broadcast address: 192.168.1.191/26 - Network: `192.168.1.0/25`
First usable address: 192.168.1.129/26 - Broadcast: `192.168.1.127`
Last usable address: 192.168.1.190/26 - Usable: `192.168.1.1 192.168.1.126`
Total Number of usable host address: 62 - Hosts: 126
##### Toronto LAN B ---
Network address: 192.168.1.192/27 ### Toronto LAN B
Broadcast address: 192.168.1.223/27 - Network: `192.168.1.128/26`
First usable address:192.168.1.193/27 - Broadcast: `192.168.1.191`
Last usable address:192.168.1.222/27 - Usable: `192.168.1.129 192.168.1.190`
Total Number of usable host address:30 - Hosts: 62
##### Tokyo LAN A ---
Network address: 192.168.1.224/28 ### Toronto LAN A
Broadcast address: 192.168.1.239/28 - Network: `192.168.1.192/27`
First usable address: 192.168.1.225 - Broadcast: `192.168.1.223`
Last usable address: 192.168.1.239 - Usable: `192.168.1.193 192.168.1.222`
Total Number of usable host address: 14 - Hosts: 30
##### Point to Point ---
Network address: 192.168.1.240/30 ### Tokyo LAN B
Broadcast address: 192.168.1.243/30 - Network: `192.168.1.224/28`
First usable address: 192.168.1.241/30 - Broadcast: `192.168.1.239`
Last usable address: 192.168.1.242/3 - Usable: `192.168.1.225 192.168.1.238`
Total Number of usable host address: 2 - Hosts: 14
---
### Point-to-Point
- Network: `192.168.1.240/30`
- Broadcast: `192.168.1.243`
- Usable: `192.168.1.241 192.168.1.242`
- Hosts: 2
---
## Additional Practice ## Additional Practice
- https://www.subnettingquestions.com - https://www.subnettingquestions.com
- https://www.subnetting.org - https://www.subnetting.org
- https://www.subnettingpractice.com - https://www.subnettingpractice.com
```