多项选择题 Which of the following commands causes a router to bring down BGP neighbor relationships?（）

多项选择题 Which of the following three BGP filtering methods enabled with the neighbor command will filter BGP prefixes based on the prefix and prefix length？（）

单项选择题 R1 is currently advertising prefixes 1.0.0.0/8, 2.0.0.0/8, and 3.0.0.0/8 over its eBGP connection to neighbor 2.2.2.2 (R2). An engineer configures a prefix list (fred) on R1 that permits only 2.0.0.0/8 and then enables the filter with the neighbor R2 prefix- list fred out command. Upon exiting configuration mode, the engineer uses some show commands on R1, but no other commands. Which of the following is true in this case?（）