多项选择题
A. A neighbor distribute - list out command, referencing a standard ACL
B. A neighbor prefix - list out command
C. A neighbor filter - list out command
D. A neighbor distribute - list out command, referencing an extended ACL
E. A neighbor route - map out command
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?（）
多项选择题 A company uses Routers R1 and R2 to connect to ISP1 and ISP2, respectively, with Routers I1 and I2 used at th e ISPs. R1 peers with I1 and R2; R2 peers with I2 and R1. R1 and R2 do not share a common subnet, relying on other routers internal to the Enterprise for IP connectivity between the two routers. Which of the following could be used to prevent potential routing loops in this design?（）
单项选择题 A company uses Routers R1 and R2 to connect to ISP1 and ISP2, respectively, with Routers I1 and I2 used at the ISPs. R1 peers with I1 and R2; R2 peers with I2 and R1. Assuming as many default s ettings as possible are used on all four routers, which of the following is true about the next - hop IP address for routes R1 learns over its iBGP connection to R2?（）