Lab 3.4.2 Configuring a Trunk Port to Connect Switches

Step 1: Connect the equipment

Step 2: Perform basic configuration of Switch 1 and Switch 2

Step 3: Configure host PCs

Step 4: Verify default VLAN configuration and connectivity

Is every switch port assigned to a VLAN?

Which VLAN do the ports appear in?

Should any host or switch be able to ping any other host or switch at this time?

Verify this by pinging from Host 1a to all the other hosts and switches.

Are all the pings successful?

Step 5: Create and verify VLAN configuration

Test connectivity between devices.

1) Ping from S1 to S2.

Are the pings successful?

To what VLAN do the management interfaces of S1 and S2 belong?

2) Ping from Host 1a to Host 2.

Are the pings successful?

To what VLAN do Hosts 1a and 2 belong?

To what VLAN do the Fa0/1 interfaces of the switches belong?

If Hosts 1a and 2 belong to the same VLAN, why can’t they ping each other?

3) Ping from host 1a to S1.

Are the pings successful?

Why can’t Host 1a ping S1?

Step 6: Configure and verify trunking

Do the trunk interfaces appear in the output?

What VLAN is set as the native VLAN?

What VLANs are allowed to communicate over the trunk?

View the VLAN configuration on both switches with the show vlan command. S1#show vlan

S2#show vlan

Do the S1 and S2 Fa0/1 interfaces appear in a VLAN? Why or why not?

Retest the connectivity between devices.

1) Ping from S1 to S2.

Are the pings successful?

2) Ping from Host 1a to Host 2.

Are the pings successful?

3) Ping from Host 1b to Host 2.

Are the pings successful?

4) Ping from Host 1a to S1.

Are the pings successful?

The ping test should show that devices that belong to the same VLAN can now communicate with each other across switches, but devices in different VLANs cannot communicate with each other.

What would have to be configured to allow devices in different VLANs to communicate with each other?

Step 7: Observe the default trunking behavior of switches

Are Fa0/1 on S1 and S2 in trunking mode?

What trunking mode did they default to?

What trunking encapsulation did they default to?

Step 8: Reflection

a. Why would trunking be configured in a network?

b. Does trunking allow for communication between VLANS?

c. With no configuration, from which VLAN are frames forwarded across the trunk without VLAN tagging added?