Illustration
The two switches in the middle are directly connected using two network cables, so that what was originally a 10G cascade becomes a 20G cascade.
By default, only one of these two lines is open under the STP protocol, and the other is in standby mode. If you want to set both channels to cascade, you need some other settings.
First create an aggregate interface on each switch
interface Bridge-Aggregation 1
port link-type trunk
port trunk permit vlan all
link-aggregation mode dynamic
Next, just add these two interfaces on the switch to the aggregation group
#
interface Ten-GigabitEthernet1/0/50
port link-type trunk
port trunk permit vlan all
port link-aggregation group 1
#
interface Ten-GigabitEthernet1/0/51
port link-type trunk
port trunk permit vlan all
port link-aggregation group 1
When you check the interface, you will find an interface called BAGG1, 20G.
<H3C>dis int brief
Brief information on interfaces in route mode:
Link: ADM - administratively down; Stby - standby
Protocol: (s) - spoofing
Interface Link Protocol Primary IP Description
InLoop0 UP UP(s) --
MGE0/0/0 DOWN DOWN --
NULL0 UP UP(s) --
REG0 UP -- --
Brief information on interfaces in bridge mode:
Link: ADM - administratively down; Stby - standby
Speed: (a) - auto
Duplex: (a)/A - auto; H - half; F - full
Type: A - access; T - trunk; H - hybrid
Interface Link Speed Duplex Type PVID Description
BAGG1 UP 20G(a) F(a) T 1
FGE1/0/53 DOWN 40G A A 1
FGE1/0/54 DOWN 40G A A 1
OK, the configuration is complete.