let's look at how to configure bundled ethernet (ae) in EVE-NG using vQFX and vMX
vmx
set chassis aggregated-devices ethernet device-count 15
set interfaces ge-0/0/0 ether-options 802.3ad ae0
set interfaces ge-0/0/1 ether-options 802.3ad ae0
set interfaces ae0 aggregated-ether-options lacp active
set interfaces ae0 unit 0 family inet address 10.10.10.1/30
vqfx
set chassis aggregated-devices ethernet device-count 15
set interfaces xe-0/0/0 ether-options 802.3ad ae0
set interfaces xe-0/0/1 ether-options 802.3ad ae0
set interfaces ae0 aggregated-ether-options lacp active
set interfaces ae0 unit 0 family inet address 10.10.10.2/30