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？（）

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?（）

A. The show ip bgp neighbor 2 .2.2.2 received -routes command lists the three original prefixes.
B. The show ip bgp neighbor 2.2.2.2 advertised - routes command lists the three original prefixes.
C. The show ip bgp neighbor 2.2.2.2 routes command lists the three original prefixes.
D. T he show ip bgp neighbor 2.2.2.2 routes command lists only 2.0.0.0/8.
E. The show ip bgp neighbor 2.2.2.2 advertised - routes command lists only 2.0.0.0/8.

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?（）

A. Using an iBGP mesh inside the Enterprise core
B. Configuring default routes in the Enterprise pointing to both R1 and R2
C. Redistributing BGP routes into the Enterprise IGP
D. Tunneling the packets for the i BGP connection between R1 and R2

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?（）

A. The next hop is I2's BGP RID
B. The next hop is I2's IP address used on the R2 - I2 neigh bor relationship
C. The next hop is R2's BGP RID
D. The next hop is R2's IP address used on the R1 - R2 neighbor relationship

多项选择题The following output on Router R1 lists details of a BGP route for 190.1.0.0 16. Which of the following is true based on this output?（） R1# show ip bgp 190.1.0.0 16 BGP routing table entry for 190.1.0.0 16, version 121 Paths: (1 available, best #1, table Default - IP - Routing - Table) Advertised to update - groups: 1 1 2 3 4 1.1.1.1 from 2.2.2.2 (3.3.3.3) Origin IGP, metric 0, localpref 100, valid, internal, best

A. R1 has a neighbor 1.1.1.1 command configured.
B. R1 has a neighbor 2.2.2.2 command configured.
C. The show ip bgp command lists a line for 190.1.0.0/16 with both a n > and an i on the left.
D. R1 is in ASN 1.