Здравствуйте!
Например 200 и 300 S-VLAN, 100 и 500 C-VLAN
Gi0/1 - Downlink
Gi0/2 - Uplink
dot1q-tunnel
vlan 1,100,200
!
interface GigaEthernet0/1
switchport trunk vlan-untagged 1,200
switchport mode dot1q-translating-tunnel
switchport dot1q-translating-tunnel mode QinQ translate 100 200 0
switchport dot1q-translating-tunnel mode QinQ translate 500 300 0
!
interface GigaEthernet0/2
switchport trunk vlan-allowed 200,300
switchport mode dot1q-tunnel-uplink