A. show ip ospf databaseB. show ip ospf interface brief……

单项选择题Which of the following is true about an OSPF area border router (ABR)?（）

A. The ABR must have multiple interfaces connected to the backbone areA
B. An ABR is a router with two interfaces, each connected to a different nonbackbone areA
C. The only requirement to be considered an  ABR is at least one interface connected to the backbone areA
D. An ABR must have at least one interface in the backbone area plus at least one other interface in a nonbackbone areA

多项选择题A router has been configured with the commands router os pf 9, network 172.16.1.0 0.0.0.255 area 8, and network 172.16.0.0 0.0.255.255 area 9, in that order. No other OSPF -related commands have been configured. The answers list the IP addresses that could be assigned to this routers Fa0 0 interface. Which an swers list an IP address prefix length that would cause the router to put Fa0 0 into area 9?（）

A. 172.16.0.1/23
B. 172.16.1.1/26
C. 172.16.1.1/24
D. 172.16.0.255/23
E. None of the other answers is correct.

多项选择题Enterprise Router R1 connects an Enterprise to the Internet. R1 needs to create and advertise a default route into the Enterprise using EIGRP. The engineer creating the implementation plan has chosen to base this default route on the ip route command, rather than using i p default - network. Which of the following is not a useful step with this style of default route configuration?（）

A. Create the default route on R1 using the ip route 0.0.0.0 0.0.0.0 outgoinginterface command.
B. Redistribute the statically configured defa ult route.
C. Disable auto - summary.
D. Configure the network 0.0.0.0 command.
E. Ensure R1 has no manually configured summary routes using the ip summary- address eigrp command.

单项选择题Router R1 exists in an Enterprise that uses EIGRP as its routing protocol. The show ip route command output on router R1 lists the following phrase: Gateway of last resort is 1.1.1.1 to network 2.0.0.0 . Whic h of the following is most likely to have caused this output to occur on R1?（）

A. R1 has been configured with an ip default- network 2.0.0.0 command.
B. R1 has been configured with an ip route 0.0.0.0 0.0.0.0 1.1.1.1 command.
C. R1 has been configured with an ip route 2.0.0.0 255.0.0.0 1.1.1.1 command.
D. Another router has been configured with an ip default - network 2.0.0.0 command.
E. Another router has been configured with an ip route 2.0.0.0 255.0.0.0 1.1.1.1 command.

多项选择题In a lab, R1 connects to R2, which connects to R3. R1 and R2 each have several working interfaces, all assigned addresses in class A network 10.0.0.0. Router R3 has some working interfaces in class A net work 10.0.0.0, and others in class B network 172.16.0.0. The engineer experiments with the auto -summary command on R2 and R3, enabling and disabling the command in various combinations. Which of the following combinations will result in R1 seeing a rout e for 172.16.0.0 16, instead of the individual subnets of class B network 172.16.0.0?（）

A. auto - summary on R2 and no auto - summary on R3
B. auto - summary on R2 and auto - summary on R3
C. no auto -summary on R2 and no auto- summary on R3
D. no auto - summary on  R2 and auto - summary on R3