单项选择题
Which command is used on the local router to invoke a loopback mode on a remote ERX Edge Router?（）
A.A B.B C.C D.D
Which command prompts an ERX Edge Router to go into a l...
Which command prompts an ERX Edge Router to go into a loopback mode on T1 number 1 when a command is received from a remote ERX Edge Router?（）
Which control expression must be the last line in all m...
Which control expression must be the last line in all macros?（）
Which command is used to execute a macro called setup.m...
Which command is used to execute a macro called setup.mac ?（）
