Today one of my Customers asked me to implement Q-in-Q on 2 EX3300-Switches.
Since more and more people asked me on the Forum how I did that, I decided to make this an Article.
Most of the J-Docs only mention parts of this config – so here you have a fully working Q-in-Q config for non-ELS.
If you are interested, I can share Q-in-Q also for ELS.

The Setup is as follows:
2 EX3300 (Q-in-Q Switches)
1 EX3300 (Transfer-Switch)
1 EX3300 and 1 EX2200 (Client-Switches)

Topology (click to enlarge):

So at first in configured Q-in-Q (of course if this is productive you need to install a license):

set system host-name EX3300-1
set chassis alarm management-ethernet link-down ignore
set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode access
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members vl-3001
set interfaces ge-0/1/0 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/1/0 unit 0 family ethernet-switching vlan members all
set protocols lldp interface all
set ethernet-switching-options dot1q-tunneling ether-type 0x8100
set vlans vl-10 vlan-id 10
set vlans vl-11 vlan-id 11
set vlans vl-12 vlan-id 12
set vlans vl-20 vlan-id 20
set vlans vl-22 vlan-id 22
set vlans vl-3001 vlan-id 3001
set vlans vl-3001 dot1q-tunneling customer-vlans 10-12
set vlans vl-3001 dot1q-tunneling customer-vlans 20
set vlans vl-3001 dot1q-tunneling customer-vlans 22
set vlans vl-3001 dot1q-tunneling customer-vlans native

set system host-name EX3300-3
set chassis alarm management-ethernet link-down ignore
set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode access
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members vl-3001
set interfaces ge-0/1/0 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/1/0 unit 0 family ethernet-switching vlan members all
set protocols lldp interface all
set ethernet-switching-options dot1q-tunneling ether-type 0x8100
set vlans vl-10 vlan-id 10
set vlans vl-11 vlan-id 11
set vlans vl-12 vlan-id 12
set vlans vl-20 vlan-id 20
set vlans vl-22 vlan-id 22
set vlans vl-3001 vlan-id 3001
set vlans vl-3001 dot1q-tunneling customer-vlans 10-12
set vlans vl-3001 dot1q-tunneling customer-vlans 20
set vlans vl-3001 dot1q-tunneling customer-vlans 22
set vlans vl-3001 dot1q-tunneling customer-vlans native

In the next step, I configured the Transit-Switch. This Switch must not be aware of any Q-in-Q or Customer VLAN’s at all:

set system host-name EX3300-2
set chassis alarm management-ethernet link-down ignore
set interfaces ge-0/1/0 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/1/0 unit 0 family ethernet-switching vlan members vl-3001
set interfaces ge-0/1/1 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/1/1 unit 0 family ethernet-switching vlan members vl-3001
set protocols lldp interface all
set vlans vl-3001 vlan-id 3001

After the Setup was completed, I tested it by adding 2 Switches as “Client-Devices” pinging each other in vlan 10:

set system host-name Client-01
set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode access
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members vl-10
set interfaces vlan unit 10 family inet address 10.10.10.1/24
set vlans vl-10 vlan-id 10
set vlans vl-10 l3-interface vlan.10

set system host-name Client-02
set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode access
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members vl-10
set interfaces vlan unit 10 family inet address 10.10.10.2/24
set vlans vl-10 vlan-id 10
set vlans vl-10 l3-interface vlan.10

Hopefully this will help some of you in configuring Q-in-Q on EX3300 (non-ELS). If you have any Questions or Remarks feel free to comment on this Article. The Switches I used all used JunOS 12.3R12.4

UPDATE:
This Article is now also officially listed in Junipers TechWiki (http://forums.juniper.net/t5/Switching/How-To-Configuring-Q-in-Q-Between-Two-EX3300-Devices/tac-p/304182#M32) 🙂