[EX/QFX] Native IRB interface is down when trunk vlan of physical interface does not include native VLAN ID in L2NG

Configurations for L2NG of native vlan:

set interfaces xe-0/1/6 native-vlan-id 100   <-- vlan 100 is native vlan
set interfaces xe-0/1/6 unit 0 family ethernet-switching interface-mode trunk
set interfaces xe-0/1/6 unit 0 family ethernet-switching vlan members 1417
set interfaces xe-0/1/6 unit 0 family ethernet-switching vlan members 1421
set interfaces xe-0/1/6 unit 0 family ethernet-switching vlan members 1433
set interfaces xe-0/1/6 unit 0 family ethernet-switching vlan members 1461-1462
set interfaces irb unit 100 family inet address 1.1.1.2/24
set interfaces irb unit 1417 family inet address 10.0.192.146/30
set interfaces irb unit 1421 family inet address 10.0.192.130/30
set interfaces irb unit 1433 family inet address 10.0.192.138/30
set interfaces irb unit 1461 family inet address 10.0.192.154/30
set interfaces irb unit 1462 family inet address 10.0.192.162/30

set vlans A14_A17 vlan-id 1417
set vlans A14_A17 l3-interface irb.1417
set vlans A14_A21 vlan-id 1421
set vlans A14_A21 l3-interface irb.1421
set vlans A14_A33 vlan-id 1433
set vlans A14_A33 l3-interface irb.1433
set vlans A14_P61 vlan-id 1461
set vlans A14_P61 l3-interface irb.1461
set vlans A14_P62 vlan-id 1462
set vlans A14_P62 l3-interface irb.1462
set vlans CRYPTO_MGMT vlan-id 100
set vlans CRYPTO_MGMT l3-interface irb.100

root@d08-26# run show interfaces irb terse
Interface               Admin Link Proto    Local                 Remote
irb                     up    up
irb.100                 up    down inet     1.1.1.2/24  <-- native vlan l3 interface is up down
irb.1417                up    up   inet     10.0.192.146/30
irb.1421                up    up   inet     10.0.192.130/30
irb.1433                up    up   inet     10.0.192.138/30
irb.1461                up    up   inet     10.0.192.154/30
irb.1462                up    up   inet     10.0.192.162/30

After adding vlan 100 in trunk vlan, it is up up:

root@d08-26# set interfaces xe-0/1/6.0 family ethernet-switching vlan members 100

{master:0}[edit]
root@d08-26# commit
configuration check succeeds
commit complete

{master:0}[edit]
root@d08-26# run show interfaces irb.100 terse
Interface               Admin Link Proto    Local                 Remote
irb.100                 up    up   inet     1.1.1.2/24

While Legacy L2 has a different behavior:

set interfaces xe-0/1/1 unit 0 family ethernet-switching port-mode trunk
set interfaces xe-0/1/1 unit 0 family ethernet-switching vlan members 1417
set interfaces xe-0/1/1 unit 0 family ethernet-switching vlan members 1421
set interfaces xe-0/1/1 unit 0 family ethernet-switching vlan members 1433
set interfaces xe-0/1/1 unit 0 family ethernet-switching vlan members 1461-1462
set interfaces xe-0/1/1 unit 0 family ethernet-switching native-vlan-id 100  <-- Native vlan is not configured under interface directly.
set interfaces vlan unit 100 family inet address 2.2.2.2/24
set interfaces vlan unit 1417 family inet address 17.0.0.1/24

set vlans v100 vlan-id 100
set vlans v100 l3-interface vlan.100
set vlans v1417 vlan-id 1417
set vlans v1417 l3-interface vlan.1417
set vlans v1421 vlan-id 1421
set vlans v1433 vlan-id 1433
set vlans v1461 vlan-id 1461
set vlans v1462 vlan-id 1462

root@d01-37# run show interfaces vlan terse
Interface               Admin Link Proto    Local                 Remote
vlan                    up    up
vlan.100                up    up   inet     2.2.2.2/24   <-- Native vlan's l3 interface is up up.
vlan.1417               up    up   inet     17.0.0.1/24

When you need to connect l3 native VLAN interface, configure add native VLAN in trunk VLAN members for L2NG code.

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