单项选择题
A. The address is a broadcast address
B. The Ehernet interface is faulty
C. VLSM-capable routing protocols must be enable first on the router.
D. This address is a network address.
单项选择题 What value is primarily used to determine which port becomes the root port on each nonroot switch in a spanning-tree topology?（）
单项选择题 Assuming default setting,how can you erase the VTP database of VLANs on a CISCO IOS switch running in VTP server mode?（）
单项选择题 Which of these represents an IPv6 link-local address?（）