Which of the following descriptions are true about SDN? (Choose all that apply.)

A. SDN is OpenFlow.

B. SDN supports forwarding-control separation.

C. SDN provides programmable open interfaces.

D. SDN is short for software-defined networking.

The SDN controller has a global view of the entire network.

A. TRUE

B. FALSE

Regarding the VS technology of CE series switches on an SDN network, which of the following statements are true? (Choose all that apply.)

A. All ports on a forwarding chip of the LPU must be allocated to the VS in Group mode at the same time.

B. All ports on a forwarding chip of the LPU must be allocated to the VS in Port mode at the same time.

C. Any LPU ports can be freely assigned at any VS in Group mode.

D. Any LPU ports can be freely assigned at any VS in Port mode.

Which of the following factors does not affect the performance of the SDN network?

A. Network congestion

B. Routing loop

C. Access loop

D. Access control list

E. Non-optional route

From the perspective of the entire Internet, which of the following methods can be effectively reduce the size of the routing tables on an SDN network?

A. Increase the frequency of updating dynamic routes

B. Divide VLANs

C. Summarize routes

Which of the following statements is true about the IS-IS backbone area?

A. A router belongs to all areas.

B. All routers belong to the same area.

C. This area comprises a series of continuous L2 routers and L1-L2 routers.

D. This area is central area connected to other areas.

OSPF and IS-IS are similar in many ways. The OSPF backbone area is indicated by area 0. Which of the following is used to indicate the IS-IS backbone area?

A. Area 0

B. Area 1

C. Area 49

D. No specific backbone area

In OSPF, which of the following statements is true within a given area (area A)?

A. The LSA generated by each router is the same.

B. The LSDB of area A of each router is the same.

C. The shortest path tree calculated based on the LSDB of each router is the same.

D. The route calculated based on each router's shortest path tree is the same.

Which statements about the link-state algorithm are true? (Choose all that apply.)

A. The link state is the description of a route.

B. The link state describes the network topology.

C. The link state algorithm does not generate route loops.

D. OSPF and RIP use the link state algorithm.

Which of the following statements are true about the meaning of the peer 20.1.1.2 allow-as-loop 2 command? (Choose all that apply.)

A. The local AS number can be repeated in the AS_Path attribute in the received routes.

B. 2 indicates the number of times the AS number can be repeated.

C. This command can only be used on EBGP peers.

D. By default, the number of times the AS number is allowed to be duplicated is 1.