CCNP Route FAQ: Internal BGP and BGP Route Filtering
Q1. R1 in ASN 1 with loopback1 address 126.96.36.199 needs to be configured with an iBGP connection to R2 with loopback2 IP address 188.8.131.52. The connection should use the loopbacks. Which of the following commands is required on R1?
a. neighbor 184.108.40.206 remote-as 1
b. neighbor 220.127.116.11 remote-as 2
c. neighbor 18.104.22.168 update-source loopback1
d. neighbor 22.214.171.124 ibgp-multihop 2
e. neighbor 126.96.36.199 ibgp-mode
Q2. The following output occurred as a result of the show ip bgp command on Router R1. The output shows all BGP table entries on R1. How many iBGP-learned routes exist on this router?
*>i188.8.131.52/8 10.100.1.1 0 100 0 1 2 111 112 i
*>i184.108.40.206/8 10.100.1.1 0 100 0 1 2 222 i
*>i220.127.116.11/8 10.100.1.1 0 100 0 1 2 i
*>i18.104.22.168/8 10.100.1.1 0 100 0 1 2 i
*> 22.214.171.124/28 192.168.1.6 0 3 4 i
Q3. The following output on Router R1 lists details of a BGP route for 126.96.36.199/16. Which of the following is true based on this output? (Choose 2)
R1# <strong>show ip bgp 188.8.131.52/16</strong>
BGP routing table entry for 184.108.40.206/16, version 121
Paths: (1 available, best #1, table Default-IP-Routing-Table)
Advertised to update-groups:
1 2 3 4
220.127.116.11 from 18.104.22.168 (22.214.171.124)
Origin IGP, metric 0, localpref 100, valid, internal, best
a. R1 has a neighbor 126.96.36.199 command configured.
b. R1 has a neighbor 188.8.131.52 command configured.
c. The show ip bgp command lists a line for 184.108.40.206/16 with both an > and an i on the left.
d. R1 is in ASN 1.
Q4. 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 settings 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 neighbor 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.
Q5. 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. 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? (Choose 2)
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 iBGP connection between R1 and R2
Q6. R1 is currently advertising prefixes 220.127.116.11/8, 18.104.22.168/8, and 22.214.171.124/8 over its eBGP connection to neighbor 126.96.36.199 (R2). An engineer configures a prefix list (fred) on R1 that permits only 188.8.131.52/8 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 184.108.40.206 received-routes command lists the three original prefixes.
b. The show ip bgp neighbor 220.127.116.11 advertised-routes command lists the three original prefixes.
c. The show ip bgp neighbor 18.104.22.168 routes command lists the three original prefixes.
d. The show ip bgp neighbor 22.214.171.124 routes command lists only 126.96.36.199/8.
e. The show ip bgp neighbor 188.8.131.52 advertised-routes command lists only 184.108.40.206/8.
Q7. Which of the following three BGP filtering methods enabled with the neighbor command will filter BGP prefixes based on the prefix and prefix length? (Choose 3)
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
Q8. Which of the following commands causes a router to bring down BGP neighbor relationships?
a. clear ip bgp *
b. clear ip bgp 220.127.116.11
c. clear ip bgp * soft
d. clear ip bgp 18.104.22.168 out