幀中繼配置路由器子接口配置不上去

[AR1]int Serial 1/0/0.1

                ^

Error: Wrong parameter found at '^' position.

[Huawei-Serial1/0/0]link-protocol fr

[Huawei]int ser 1/0/0.1

May 12 2017 15:26:07-08:00 Huawei %%01IFNET/4/LINK_STATE(l)[5]:The line protocol

 IP on the interface Serial1/0/0.1 has entered the DOWN state. 

[Huawei-Serial1/0/0.1]

爲何下面這個就能夠了呢？ 

[Huawei-Serial1/0/0]link-protocol fr  要這個接口在fr協議下才能配置子接口

Warning: The encapsulation protocol of the link will be changed. Continue? [Y/N]

:y

May 12 2017 15:25:54-08:00 Huawei %%01IFNET/4/CHANGE_ENCAP(l)[0]:The user perfor

med the configuration that will change the encapsulation protocol of the link an

d then selected Y. 

[Huawei-Serial1/0/0]