Refer to the exhibit. On the basis of the information in the exhibit, which two statements are
true? (Choose two.)
A.
The output was generated by entering the show ip bgp command on the ISP router.
B.
The output was generated by entering the show ip bgp command on the SanJose1
router.
C.
The serial 0/0/1 interface on the ISP router has been configured with the set metric 50
command.
D.
The serial 0/0/1 interface on the ISP router has been configured with the set metric 75
command.
E.
When traffic is sent from the ISP to autonomous system 64512, the traffic will be
forwarded to SanJose1 because of the lower MED value of SanJose1.
F.
When traffic is sent from the ISP to autonomous system 64512, the traffic will be
forwarded to SanJose2 because of the higher MED value of SanJose2.
Explanation:
From the output, we notice that the “local router ID” is 192.168.100.1 which is an interface
on ISP router -> A is correct.
The show ip bgpcommand is used to display entries in the Border Gateway Protocol
(BGP) routing table
Multi-Exit Discriminator (MED) is used when we havemultiple entry points (connections) to
another AS. A lower MED value is preferred over a higher value. Notice that the comparison
between the MED only occurs if the first AS is the same in two (or more) paths. In this
question, the first AS is 64512 which is the same -> the comparison can occur.
From the output, we learn that ISP router is receiving the 172.16.0.0 network from
SanJose1 (192.168.1.6) with a metric of 50 and fromSanJose2 (192.168.1.2) with a metric
of 75. Also note that BGP has chosen the best path 192.168.1.6 to the 172.16.0.0 network
(the “>” indicates it is the best path). The Weight, Local Preference (LocPrf) and AS-Path
values between two next hops (192.168.1.2 & 192.168.1.6) are the same so we can deduce
the traffic from ISP is sent from the ISP to SanJose1 because of the lower MED value.
Note: An entry of 0.0.0.0 in the “Next Hop” indicates that the router has some non-BGP
routes to this network.