Refer to the exhibit.
S1#show interface trunk
Port Mode Encapsulation Status Native vlan
Fa0/1 on 802.1q trunking 1
Port Vlans allowed on trunk
Fa0/1 1,105
Port Vlans allowed and active in management domain
Fa0/1 12
S2#show interface trunk
Port Mode Encapsulation Status Native vlan
Fa0/1 on 802.1q trunking 2
Port Vlans allowed on trunk
Fa0/1 1,105
Port Vlans allowed and active in management domain
Fa0/1 12
A frame on VLAN 1 on switch S1 is sent to switch S2 where the frame is received on VLAN 2. What causes this behavior?