Below is a working Q-in-Q config for an EX4600 (ELS) switch. Config should be same for EX4300 (again ELS switch). Hopefully this can help you.
SVLAN == 4020
CVLAN ==1-4000
ae0.4020 == double tagged interface
ae1.0 == single tagged interface
{master:0}[edit vlans]
mit@ServiceEdge-C2A# show LLAN
interface ae0.4020;
interface ae1.0;
domain-type bridge;
{master:0}[edit vlans]
mit@ServiceEdge-C2A# top show interfaces ae0
description Uplink-Edge;
flexible-vlan-tagging;
mtu 9192;
encapsulation extended-vlan-bridge;
aggregated-ether-options {
lacp {
active;
periodic fast;
}
}
unit 4020 {
vlan-id 4020;
}
{master:0}[edit vlans]
mit@ServiceEdge-C2A# top show interfaces ae1
flexible-vlan-tagging;
encapsulation extended-vlan-bridge;
aggregated-ether-options {
lacp {
active;
periodic fast;
}
}
unit 0 {
vlan-id-list 1-4000;
input-vlan-map push;
output-vlan-map pop;
}