Private IP-Adresse

Nerd Cafe | نرد کافه

1. Private IP Addressing Introduction

Class	Private Range	Default Mask	Use in This Lab
Class A	10.0.0.0 – 10.255.255.255	255.0.0.0	Used for WAN link (10.0.0.0/30)
Class B	172.16.0.0 – 172.31.255.255	255.255.0.0	Used for Server Farm (172.16.11.0/24)
Class C	192.168.0.0 – 192.168.255.255	255.255.255.0	Used for PCs: 192.168.1.0/24 and 192.168.2.0/24

2. Scenario Overview

• Goal: Practice how private IP addresses are applied in real networks. You will use:

  • LANs (Class C Private Address) for departments

  • Server subnet (Class B Private IP Address) for DNS/HTTP servers

  • WAN (Class A Private IP Address) between routers R1 and R2

• Design:

  • Three VLANs:

    • Server-Farm (VLAN 2)

    • Computer-Dept (VLAN 3)

    • Physics-Dept (VLAN 4)

  • Core switch connecting everything with trunks

  • Router R1 does Router-on-a-Stick (subinterfaces for inter-VLAN routing)

  • R1 connected to R2 through WAN 10.0.0.0/30

3. Network Topology

4. Addressing Plan

Device	IP Address	Mask	Gateway
PC1 (VLAN 3)	192.168.1.100	/24	192.168.1.1
PC2 (VLAN 3)	192.168.1.101	/24	192.168.1.1
PC3 (VLAN 4)	192.168.2.100	/24	192.168.2.1
PC4 (VLAN 4)	192.168.2.101	/24	192.168.2.1
DNS Server	172.16.11.10	/24	172.16.11.1
HTTP Server	172.16.11.11	/24	172.16.11.1
R1 fa0/0.1 (VLAN 3)	192.168.1.1	/24	-
R1 fa0/0.2 (VLAN 4)	192.168.2.1	/24	-
R1 fa0/0.3 (VLAN 2)	172.16.11.1	/24	-
R1 S0/0/0	10.0.0.1	/30	-
R2 S0/0/0	10.0.0.2	/30	-

5. Device Configurations

A) Core Switch (SW-Core)

MLS>enable 
MLS#configure terminal 
MLS(config)#hostname SW-Core
SW-Core(config)#vlan 2
SW-Core(config-vlan)#name Server-Farm
SW-Core(config-vlan)#exit
SW-Core(config)#vlan 3
SW-Core(config-vlan)#name Computer-Dept
SW-Core(config-vlan)#exit
SW-Core(config)#vlan 4
SW-Core(config-vlan)#name Physics-Dept
SW-Core(config-vlan)#exit
SW-Core(config)#interface fastEthernet 0/1
SW-Core(config-if)#description T-Server-Farm
SW-Core(config-if)#switchport trunk encapsulation dot1q 
SW-Core(config-if)#switchport mode trunk 
SW-Core(config-if)#switchport trunk allowed vlan 2,3,4
SW-Core(config-if)#exit
SW-Core(config)#interface fastEthernet 0/3
SW-Core(config-if)#description To-Physics-Dept
SW-Core(config-if)#switchport trunk encapsulation dot1q 
SW-Core(config-if)#switchport mode trunk 
SW-Core(config-if)#switchport trunk allowed vlan 2,3,4
SW-Core(config-if)#exit
SW-Core(config)#interface fastEthernet 0/4
SW-Core(config-if)#description To-R1
SW-Core(config-if)#switchport trunk encapsulation dot1q 
SW-Core(config-if)#switchport mode trunk 
SW-Core(config-if)#switchport trunk allowed vlan 2,3,4
SW-Core(config-if)#^Z
SW-Core#write memory 
Building configuration...
[OK]
SW-Core#

B) Server Farm Switch

Sw-Server-Farm>enable 
Sw-Server-Farm#configure terminal 
Sw-Server-Farm(config)#hostname SW-ServerFarm
SW-ServerFarm(config)#interface fastEthernet 0/1
SW-ServerFarm(config-if)#switchport mode access 
SW-ServerFarm(config-if)#switchport access vlan 2
SW-ServerFarm(config-if)#spanning-tree portfast 
SW-ServerFarm(config-if)#exit
SW-ServerFarm(config)#interface fastEthernet 0/2
SW-ServerFarm(config-if)#switchport mode access 
SW-ServerFarm(config-if)#switchport access vlan 2
SW-ServerFarm(config-if)#spanning-tree portfast 
SW-ServerFarm(config-if)#exit
SW-ServerFarm(config)#interface fastEthernet 0/3
SW-ServerFarm(config-if)#description To-Core
SW-ServerFarm(config-if)#switchport mode trunk 
SW-ServerFarm(config-if)#switchport trunk allowed vlan 2,3,4
SW-ServerFarm(config-if)#^Z
SW-ServerFarm#write memory 
Building configuration...
[OK]
SW-ServerFarm#

C) Computer Dept Switch

Sw-Computer-Dep>enable 
Sw-Computer-Dep#configure terminal 
Sw-Computer-Dep(config)#interface fastEthernet 0/1
Sw-Computer-Dep(config-if)#switchport mode access 
Sw-Computer-Dep(config-if)#switchport access vlan 3
Sw-Computer-Dep(config-if)#spanning-tree portfast 
Sw-Computer-Dep(config-if)#exit
Sw-Computer-Dep(config)#interface fastEthernet 0/2
Sw-Computer-Dep(config-if)#switchport mode access 
Sw-Computer-Dep(config-if)#switchport access vlan 3
Sw-Computer-Dep(config-if)#spanning-tree portfast 
Sw-Computer-Dep(config-if)#exit
Sw-Computer-Dep(config)#interface fastEthernet 0/3
Sw-Computer-Dep(config-if)#switchport mode trunk 
Sw-Computer-Dep(config-if)#switchport trunk allowed vlan 2,3,4
Sw-Computer-Dep(config-if)#^Z
Sw-Computer-Dep#write memory 
Building configuration...
[OK]
Sw-Computer-Dep#

D) Physics Dept Switch

Sw-Physics-Dep>enable 
Sw-Physics-Dep#configure terminal 
Sw-Physics-Dep(config)#hostname Sw-Physics-Dep
Sw-Physics-Dep(config)#interface fastEthernet 0/1
Sw-Physics-Dep(config-if)#switchport mode access 
Sw-Physics-Dep(config-if)#switchport access vlan 4
Sw-Physics-Dep(config-if)#spanning-tree portfast 
Sw-Physics-Dep(config-if)#exit
Sw-Physics-Dep(config)#interface fastEthernet 0/2
Sw-Physics-Dep(config-if)#switchport mode access 
Sw-Physics-Dep(config-if)#switchport access vlan 4
Sw-Physics-Dep(config-if)#spanning-tree portfast 
Sw-Physics-Dep(config-if)#exit
Sw-Physics-Dep(config)#interface fastEthernet 0/3
Sw-Physics-Dep(config-if)#description To-Core
Sw-Physics-Dep(config-if)#switchport mode trunk 
Sw-Physics-Dep(config-if)#switchport trunk allowed vlan 2,3,4
Sw-Physics-Dep(config-if)#^Z
Sw-Physics-Dep#write memory 
Building configuration...
[OK]
Sw-Physics-Dep#

E) Router R1 (Router-on-a-Stick)

Router>enable 
Router#configure terminal
Router(config)#no ip domain-lookup 
Router(config)#interface fastEthernet 0/0
Router(config-if)#no ip address 
Router(config-if)#no shutdown 
Router(config-if)#exit 
Router(config)#interface fastEthernet 0/0.1
Router(config-subif)#encapsulation dot1Q 3
Router(config-subif)#ip address 192.168.1.1 255.255.255.0
Router(config-subif)#exit
Router(config)#interface fastEthernet 0/0.2
Router(config-subif)#encapsulation dot1Q 4
Router(config-subif)#ip address 192.168.2.1 255.255.255.0
Router(config-subif)#exit
Router(config)#interface fastEthernet 0/0.3
Router(config-subif)#encapsulation dot1Q 2
Router(config-subif)#ip address 172.16.11.1 255.255.255.0
Router(config-subif)#exit
Router(config)#interface serial 0/0/0
Router(config-if)#ip address 10.0.0.1 255.255.255.252
Router(config-if)#no shutdown 
Router(config-if)#exit
Router(config)#ip route 0.0.0.0 0.0.0.0 serial 0/0/0
Router(config)#^Z
Router#write memory 
Building configuration...
[OK]
Router#

F) Router R2

Router>enable 
Router#configure terminal 
Router(config)#hostname R2
R2(config)#interface s0/0/0
R2(config-if)#ip address 10.0.0.2 255.255.255.252
R2(config-if)#no shutdown 
R2(config-if)#exit
R2(config)#ip rout
R2(config)#ip route 192.168.1.0 255.255.255.0 10.0.0.1
R2(config)#ip route 192.168.2.0 255.255.255.0 10.0.0.1
R2(config)#ip route 172.16.11.0 255.255.255.0 10.0.0.1
R2(config)#^Z
R2#write memory 
Building configuration...
[OK]
R2#

6. End Device Configuration

On each PC:

• IP address = from addressing table

• Subnet mask = 255.255.255.0

• Default gateway = R1’s subinterface for that VLAN

• DNS = 172.16.11.10

Example PC1:

IP: 192.168.1.100
Mask: 255.255.255.0
Gateway: 192.168.1.1
DNS: 172.16.11.10

Servers:

DNS: 172.16.11.10/24, GW = 172.16.11.1
HTTP: 172.16.11.11/24, GW = 172.16.11.1

7. Testing & Verification

PC>ping 192.168.1.101

Pinging 192.168.1.101 with 32 bytes of data:

Reply from 192.168.1.101: bytes=32 time=0ms TTL=128
Reply from 192.168.1.101: bytes=32 time=0ms TTL=128

PC>ping 192.168.2.100

Pinging 192.168.2.100 with 32 bytes of data:

Reply from 192.168.2.100: bytes=32 time=1ms TTL=127
Reply from 192.168.2.100: bytes=32 time=0ms TTL=127

PC>ping 192.168.2.101

Pinging 192.168.2.101 with 32 bytes of data:

Reply from 192.168.2.101: bytes=32 time=0ms TTL=127
Reply from 192.168.2.101: bytes=32 time=0ms TTL=127

PC>ping 172.16.11.10

Pinging 172.16.11.10 with 32 bytes of data:

Reply from 172.16.11.10: bytes=32 time=0ms TTL=127
Reply from 172.16.11.10: bytes=32 time=1ms TTL=127

PC>ping 172.16.11.11

Pinging 172.16.11.11 with 32 bytes of data:

Reply from 172.16.11.11: bytes=32 time=1ms TTL=127
Reply from 172.16.11.11: bytes=32 time=0ms TTL=127

PC>

8. Cisco Packet Tracer (Version 6.2.0.0052)

149KB

Private-IP-Address.pkt

Open

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Keywords

Network IP , Broadcast IP , First IP (usable) , Last IP (usable) , Number of available IPs (hosts) , Subnet mask , Nerd Cafe , نرد کافه

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