VLAN communication problem

[perelt]

Hi,

Here is the the configuration 

** Router **

interface gigabitEthernet 0/1.1
encapsulation dot1Q 10
ip address 192.168.10.1 255.255.255.0
!
interface gigabitEthernet 0/1.2
encapsulation dot1Q 20
ip address 192.168.20.1 255.255.255.0
!

**Switch1**

vlan 10
name 10
!
interface fastEthernet 0/1
switchport access vlan 10
!
switchport mode trunk
switchport trunk allowed vlan 10
!

**Switch2**

vlan 20
name 20
!
interface fastEthernet 0/1
switchport access vlan 20
!
switchport mode trunk
switchport trunk allowed vlan 20
!
**Switch3**

interface range fastEthernet 0/1-3
switchport mode trunk
switchport trunk allowed vlan 10,20
!

I can't ping pc to pc. Could you tell me what i did wrong?

[Georg Pauwen]

Hello,

Packet Tracer has some quirks. Change the subinterfaces to:

interface gigabitEthernet 0/1.10
encapsulation dot1Q 10
ip address 192.168.10.1 255.255.255.0
!
interface gigabitEthernet 0/1.20
encapsulation dot1Q 20
ip address 192.168.20.1 255.255.255.0

If that doesn't work, post the zipped Packet Tracer project (.pkt) file.

[perelt]

I changed the subinterfaces and there is still something wrong.

[Georg Pauwen]

Hello,

the problem was that Vlan 10 did not exist on Switch 1, and Vlan 20 did not exist on Switch 2. When you assign a Vlan to a port in access mode, the Vlan is automatically created. Since you have configured the links between the PCs and the switches as trunks, you have to manually create the Vlans.

Attached the working file.