单项选择题
A. duplex mismatch
B. a routing loop
C. trunking mode mismatch
D. improperly configured root bridge
E. improperly configured static VLAN
多项选择题 While troubleshooting connectivity issues, you log into a remote router. From there,you wish to see the layer 1 and layer 2 status of the interface. Which of the following IOS commands would you issue to check the current IP addressing, as well as theyer 1 and layer 2 status of an interface?（）
单项选择题 While troubleshooting a connectivity issue from a PC you obtain the following information: Local PC IP address: 190.0.3.35/24 Default Gateway: 190.0.3.1 Remote Server: 190.0.5.250/24 You then conduct the following tests from the local PC: Ping 127.0.0.1 - Unsuccessful Ping 190.0.3.35 - Successful Ping 190.0.3.1 - Unsuccessful Ping 190.0.5.250 - Unsuccessful What is the underlying cause of this problem?（）
多项选择题 Part of the configuration files for routers testking1 and testking2 are displayed below: If you were to enter the "show interface serial 0" command on router testking1,which of the following will be displayed?（）