Vsu配置：
建立VSU:
S3核心一(主)：
ena
conf t
switch virtual domain 1 ---------域名设置
switch 1 description S6000C-1 -------添加描述
switch 1 priority 120 -------设置优先级
exit
vsl-port
port-member interface te0/49 -------我把te0/49-50作为vsu链路
port-member interface te0/50
ex
switch convert mode virtual ------切换为vsu模式
y
n
S4核心二（备）：
ena
conf t
switch virtual domain 1
switch 2 description S6000C-2
switch 2 priority 100
exit
vsl-port
port-member interface te0/49
port-member interface te0/50
ex
switch convert mode virtual
y
n
配置链路的BFD：
ena
conf t
int gi1/0/48
no switch
exit
int gi 2/0/48
no switch
exit
switch virtual domain 1
dual-active detection bfd
dual-active bfd int gi1/0/48
dual-active bfd int gi2/0/48
exit
