单项选择题
A.A
B.B
C.C
D.D
单项选择题 Which CLI command displays FECN and BECN information on a Frame Relay interface configured on serial interface 4/0:3/1 ?（）
多项选择题 Which two services protect the ERX Edge Router from unauthorized CLI logins?（）
多项选择题 Which two features protect the ERX Edge Router from denial-of-service attacks?（）
