Compared with the OSPF protocol. Which of the following characteristics does the IS-IS protocol have? (Multiple choice)
A . The SPF algorithm is used in the same area. Routes between areas need to be forwarded through the backbone area.
B . Both Level-1 and Level-2 routes use the SPF algorithm to generate the Shortest Path Tree (SPT).
C . In IS-IS, each router belongs to only one area.
D . Different interfaces of a router can belong to different areas
Answer: BD