If you first configure a QinQ interface and then later try to change the ethertype to 802.1q the ethertype is not changed.
set interfaces ethernet eth0 vif-s 700 vif-c 20 address 10.0.0.1/24 commit set interfaces ethernet eth0 vif-s 700 protocol 802.1q commit sudo ip -d link show dev eth0.700 13: eth0.700@eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000 link/ether 00:0d:b9:5a:2e:54 brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 0 maxmtu 65535 vlan protocol 802.1ad id 700 <REORDER_HDR> addrgenmode none numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
If you configure 802.1q first the ethertype is set correct.
set interfaces ethernet eth0 vif-s 700 protocol '802.1q' set interfaces ethernet eth0 vif-s 700 vif-c 20 address '10.0.0.1/24' commit sudo ip -d link show dev eth0.700 15: eth0.700@eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000 link/ether 00:0d:b9:5a:2e:54 brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 0 maxmtu 65535 vlan protocol 802.1Q id 700 <REORDER_HDR> addrgenmode none numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535