Co tohle:
/interface ethernet
set ether2 master-port=ether1
set ether3 master-port=ether1
set ether4 master-port=ether1
set ether5 master-port=ether1
/interface ethernet switch port
set switch1-cpu vlan-mode=secure vlan-header=always-strip default-vlan-id=1
set ether1 vlan-mode=secure vlan-header=always-strip default-vlan-id=1
set ether2 vlan-mode=secure vlan-header=always-strip default-vlan-id=1
set ether3 vlan-mode=secure vlan-header=always-strip default-vlan-id=1
set ether4 vlan-mode=secure vlan-header=leave-as-is default-vlan-id=1
set ether5 vlan-mode=secure vlan-header=always-strip default-vlan-id=2990
/interface ethernet switch vlan
add ports=switch1-cpu,ether1,ether2,ether3,ether4 switch=switch1 vlan-id=1
add ports=ether4,ether5 switch=switch1 vlan-id=2990