A network admin wants to know every hop the packets take when he accesses cisco.com. Which command is the most appropriate to use?（）

单项选择题Which line from the output of the show ip interface command indicates a layer 1 problem?（）

A. Serial0/1 is up, line protocol is down
B. Serial0/1 is down, line protocol is down
C. Serial0/1 is up, line protocol is up
D. Serial0/1 is administratively down, line protocol is down

单项选择题Which statement about IPv6 is true?（）

A. Addresses are not hierarchical and are assigned at random.
B. Only one IPv6 address can exist on a given interface.
C. There are 2.7 billion addresses available.
D. Broadcasts have been eliminated and replaced with multicasts.

单项选择题Which statement about RIPng is true?（）

A. RIPng allows for routes with up to 30 hops.
B. RIPng is enabled on each interface separately.
C. RIPng uses broadcasts to exchange routes.
D. There can be only one RIPng process per router.

单项选择题Which term describes the process of encapsulating IPv6 packets inside IPv4 packets?（）

A. tunneling
B. hashing
C. routing
D. NAT

单项选择题What is the first 24 bits in a MAC address called?（）

A. NIC
B. BIA
C. OUI
D. VAI