Summary:

 

1. Manually configure trunk ports between S1, S2, and S3
2. Add the following VLANs to S1, S2, and S3. Ensure these VLANs (and the default VLAN) are the only VLANs allowed to pass between all switches. You can optionally use VTP to save some configuration time.
    • VLAN2 – IT (10.24.2.0/24)
    • VLAN5 – Accounting (10.24.5.0/24)

 

NOTE: The EtherSwitch module used for switch emulation in GNS3 uses the vlan database mode for VLAN configuration.

 

Knowledge:

VTP: to replicate vlans across switches. I.e. you add one vlan (accounting) on one switch, VTP will automatically replicate the accounting vlan across all connected switches (do not enable this feature)

VTP modes:

    Client: no ability to modify the vlan database

    Server: default mode, can modify the vlan database

    Transparent: this is to disable the VTP

Some VTP commands:

    show vtp status

    vtp mode tranparent

1. Manually configure trunk ports among S1, S2, and S3

S1.

int fa1/1
 switchport mode trunk
int fa1/2
 switchport mode trunk


S2.

int fa1/0
 switchport mode trunk


S3.

int fa1/0
 switchport mode trunk

#Test:

2.1 Add the following VLANs to S1, S2, and S3 using VTP.

• VLAN2 – IT (10.24.2.0/24)   

• VLAN5 – Accounting (10.24.5.0/24

Note: you need to add more flash space in GNS3 for this to work. Make sure to

    1. reboot the switches after adding flash space;

    2. run command "erase flash:";

 

S1.

vlan database
 vtp domain TECHCANBEFUN
 vlan 2 name IT !!!! To create a VLAN
 vlan 5 name ACCOUNTING

S2.

vlan database
 vtp domain TECHCANBEFUN

S3.

vlan database
 vtp domain TECHCANBEFUN

Note: since all three switches are in vtp server mode and same domain, both S2 and S3 will automatically get a copy of vlan info from S1

 

2.2. Ensure these VLANs (and the default VLAN) are the only VLANs allowed to pass between all switches.

 

S1.

show cdp neighbors !--------------------find out which ports are trunk ports (directly connected to other switches)
interface range fastEthernet 1/1 - 2
 switchport trunk allowed vlan 1-2,5,1002-1005


S2.
int fa1/0
switchport trunk allowed vlan 1-2,5,1002-1005


S3.

int fa 1/0
switchport trunk allowed vlan 1-2,5,1002-1005

#Test:

 

-Yu