单项选择题 Refer to the exhibit. Routers R1 and R2 have been configured to operate with OSPF. Routers R1 and R3 have been configured to operate with RIP. After configuring the redistribution between OSPF a nd RIP on R1, no OSPF routes are distributed into RIP. What should be done to correct this problem? （）

单项选择题 Refer to the exhibit. What is required to complete the IPv6 routing configurations shown?（）

单项选择题 Refer to the parti al configurations in the exhibit. What address is utilized for DR and BDR identification on Router1?（）