单项选择题 How can an administrator determine if a router has been configured when it is first powered up?（）

单项选择题 When is a switched network that is running the Spanning Tree Protocol considered to be fully converged?（）

单项选择题 At a branch location, TestKing.com has deployed a non modular router that is equipped with two serial interfaces and two Ethernet interfaces.What additional equipment must be used to allow the branch office to connect to the central office by using an ISDN service?（）