关于汇聚交换机的问题在线等

wsxbdz

最近在自学大汇聚交换的看到配置，知道上联口和下联口，但是下联口的数据是如何在汇聚交换中转发到上联口的，求高手解惑
以下是配置，求解答。
汇聚交换机为8908

interface smartgroup9
  out_index 112
  description to_Q_MA5680T-2
  switchport mode trunk
  switchport trunk native vlan 4008
  switchport trunk vlan 7
  switchport trunk vlan 11
  switchport trunk vlan 33
  switchport trunk vlan 131
  switchport trunk vlan 2368-2431 FTTB
  switchport trunk vlan 3112-3119 FTTH
  switchport trunk vlan 3240-3247 FTTH
  smartgroup mode 802.3ad
interface gei_4/2
  out_index 4
  description to_Q_MA5680T-2(GE0/10/0)
  no negotiation auto
  switchport mode trunk
  switchport trunk native vlan 4008
  switchport trunk vlan 7
  switchport trunk vlan 11
  switchport trunk vlan 33
  switchport trunk vlan 131
  switchport trunk vlan 2368-2431
  switchport trunk vlan 3112-3119
  switchport trunk vlan 3240-3247
  switchport qinq normal
  smartgroup 9 mode active
!

interface gei_4/20
  out_index 22
  description to_ME60X8-A-Q (Gi_7/0/7)
  no negotiation auto
  switchport mode trunk
  switchport trunk native vlan 4018
  switchport trunk vlan 3-499
  switchport trunk vlan 600-4094
  switchport qinq uplink
  smartgroup 18 mode active
!
interface gei_4/21
  out_index 23
  description to_ME60X8-A-Q (Gi_7/0/8)
  no negotiation auto
  switchport mode trunk
  switchport trunk native vlan 4018
  switchport trunk vlan 3-499
  switchport trunk vlan 600-4094
  switchport qinq uplink
  smartgroup 18 mode active
!
interface gei_4/22
  out_index 24
  description to_ME60X8-A-Q (Gi_7/0/9)
  no negotiation auto
  switchport mode trunk
  switchport trunk native vlan 4018
  switchport trunk vlan 3-499
  switchport trunk vlan 600-4094
  switchport qinq uplink
  smartgroup 18 mode active