单项选择题 You would like to configure an Ethernet interface with the following characteristics: Fast Which set of configuration commands accurately completes this task?（）

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?（）