This article provides information about Q-in-Q (dot1q tunnel). It is used to tag traffic, from multiple customers, aggregating on a single interface into separate SVLANs.
Topology:

- Customer 1 and Customer 2 traffic is aggregated on the CPE1 and the Service Provider PE1 is receiving both customers’ traffic on the single interface ge-0/0/2.
- Customer 1 traffic with VLAN tags 10 & 20 will be double tagged using SVLAN 3001 and customer2 traffic with VLAN tags 30 & 40 will be double tagged with SVLAN 3002.
- PE2 and PE3 will remove the respective SVLAN tags before sending the traffic to the respective customers.
Configuration:
CPE1:
set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members all
PE1:
set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members all
set interfaces ge-0/0/1 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/1 unit 0 family ethernet-switching vlan members all
set interfaces ge-0/0/2 unit 0 family ethernet-switching
set vlans svlan1 vlan-id 3001
set vlans svlan1 interface ge-0/0/2.0
set vlans svlan1 dot1q-tunneling customer-vlans 10
set vlans svlan1 dot1q-tunneling customer-vlans 20
set vlans svlan2 vlan-id 3002
set vlans svlan2 interface ge-0/0/2.0
set vlans svlan2 dot1q-tunneling customer-vlans 30
set vlans svlan2 dot1q-tunneling customer-vlans 40
set ethernet-switching-options dot1q-tunneling ether-type 0x8100
PE2:
set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members all
set interfaces ge-0/0/1 unit 0 family ethernet-switching
set vlans svlan1 vlan-id 3001
set vlans svlan1 interface ge-0/0/1.0
set vlans svlan1 dot1q-tunneling customer-vlans 10
set vlans svlan1 dot1q-tunneling customer-vlans 20
set ethernet-switching-options dot1q-tunneling ether-type 0x8100
PE3:
root@3200-5# run show vlans dot1q-tunneling extensive
VLAN: svlan2, Created at: Sun Jan 3 20:46:17 2010
802.1Q Tag: 3002, Internal index: 4, Admin State: Enabled, Origin: Static
Dot1q Tunneling status: Enabled
Customer VLAN ranges:
30-30
40-40
Protocol: Port Mode, Mac aging time: 300 seconds
Number of interfaces: Tagged 1 (Active = 1), Untagged 1 (Active = 1)
ge-0/0/0.0*, tagged, trunk
ge-0/0/1.0*, untagged, access
Create RVI on CPEs and verify using ping:
CPE1:
set interfaces vlan unit 10 family inet address 10.10.10.19/24
set interfaces vlan unit 30 family inet address 30.30.30.19/24
CPE2:
set interfaces vlan unit 10 family inet address 10.10.10.17/24
CPE3:
set interfaces vlan unit 30 family inet address 30.30.30.4/24
Ping from CPE1 to CPE2:
root# ping 10.10.10.17
64 bytes from 10.10.10.17: icmp_seq=0 ttl=53 time=2.785 ms
64 bytes from 10.10.10.17: icmp_seq=0 ttl=53 time=1.705 ms
Ping from CPE1 to CPE3:
root# ping 30.30.30.4
64 bytes from 30.30.30.4: icmp_seq=0 ttl=53 time=2.785 ms
64 bytes from 30.30.30.4: icmp_seq=0 ttl=53 time=1.115 ms