单项选择题 A network administrator is designing a Cisco network for a large company. The network must be able to use minimal bandwidth for routing updates, converge quickly, and support VLSM, CIDR, IP and IPX. Which routing protocol will best fit the requirements of this network?（）

单项选择题 You are unable to telnet to a router at address 203.125.12.1 from a workstation with the IP address 203.125.12.23. You suspect that there is a problem with your protocol stack. Which of the following actions is most likely to confirm your diagnosis?（）

单项选择题 Why would an administrator change the value of the spanning-tree priority of a switch?（）