单项选择题
A. An IPv6 address is 64 b long and is represented as hexadecimal characters.
B. An IPv6 address is 32 b long and is represented as decimal digits.
C. An IPv6 address is 128 b long and is represented as decimal digits.
D. An IPv6 address is 128 b long and is represented as hexadecimal characters.
单项选择题 When upgrading the IOS image, the network administrator receives the exhibited error message. What could be the cause of this error?（）
单项选择题 This graphic shows the results of an attempt to open a Telnet connection to router ACCESS1 from router Remote27. Which of the following command sequences will correct this problem? （）
单项选择题 A network administrator is troubleshooting the OSPF configuration of routers R1 and R2. The routers cannot establish an adjacency relationship on their common Ethernet link. The graphic shows the output of the show ip ospf interface e0 command for routers R1 and R2. Based on the information in the graphic, what is the cause of this problem?（）