Q1. Refer to the exhibit. The network setup is running the RIP routing protocol. Which two events will occur following link failure between R2 and R3? (Choose two.)
A. R2 will advertise network 192.168.2.0/27 with a hop count of 16 to R1.
B. R2 will not send any advertisements and will remove route 192.168.2.0/27 from its routing table.
C. R1 will reply to R2 with the advertisement for network 192.168.2.0/27 with a hop count of 16.
D. After communication fails and after the hold-down timer expires, R1 will remove the 192.168.2.0/27 route from its routing table.
E. R3 will not accept any further updates from R2, due to the split-horizon loop prevention mechanism.
Answer: A,C
Explanation:
Q2. A network engineer has been asked to ensure that the PPPoE connection is established and authenticated using an encrypted password. Which technology, in combination with PPPoE, can be used for authentication in this manner?
A. PAP
B. dot1x
C. IPsec
D. CHAP
E. ESP
Answer: D
Explanation:
With PPPoE, the two authentication options are PAP and CHAP. When CHAP is enabled on
an interface and a remote device attempts to connect to it, the access server sends a CHAP packet to the
remote device. The CHAP packet requests or "challenges" the remote device to respond. The challenge
packet consists of an ID, a random number, and the host name of the local router. When the remote device
receives the challenge packet, it concatenates the ID, the remote device's password, and the random
number, and then encrypts all of it using the remote device's password. The remote device sends the
results back to the access server, along with the name associated with the password used in the
encryption process. When the access server receives the response, it uses the name it received to retrieve
a password stored in its user database. The retrieved password should be the same password the remote
device used in its encryption process. The access server then encrypts the concatenated information with
the newly retrieved password--if the result matches the result sent in the response packet, authentication
succeeds. The benefit of using CHAP authentication is that the remote device's password is never
transmitted in clear text (encrypted). This prevents other devices from stealing it and gaining illegal access
to the ISP's network. Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_2/security/configuration/
guide/fsecur_c/scfathen.ht ml
Q3. Under which condition does UDP dominance occur?
A. when TCP traffic is in the same class as UDP
B. when UDP flows are assigned a lower priority queue
C. when WRED is enabled
D. when ACLs are in place to block TCP traffic
Answer: A
Explanation:
Explanation: Mixing TCP with UDP It is a general best practice to not mix TCP-based traffic with UDPbased
traffic (especially Streaming-Video) within a single service-provider class because of the behaviors
of these protocols during periods of congestion. Specifically, TCP transmitters throttle back flows when
drops are detected. Although some UDP applications have application-level windowing, flow control, and
retransmission capabilities, most UDP transmitters are completely oblivious to drops and, thus, never lower
transmission rates because of dropping. When TCP flows are combined with UDP flows within a single
service-provider class and the class experiences congestion, TCP flows continually lower their
transmission rates, potentially giving up their bandwidth to UDP flows that are oblivious to drops. This
effect is called TCP starvation/UDP dominance. TCP starvation/UDP dominance likely occurs if (TCP-based) Mission-Critical Data is assigned to the same service-provider class as (UDP-based) Streaming-
Video and the class experiences sustained congestion. Even if WRED is enabled on the service-provider
class, the same behavior would be observed because WRED (for the most part) manages congestion only
on TCP-based flows. Reference: http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/
WAN_and_MAN/QoS_SRND/QoS- SRND-Book/VPNQoS.html
Topic 2, Layer 2 Technologies
13. Prior to enabling PPPoE in a virtual private dialup network group, which task must be completed?
A. Disable CDP on the interface.
B. Execute the vpdn enable command.
C. Execute the no switchport command.
D. Enable QoS FIFO for PPPoE support.
Q4. For security purposes, an IPv6 traffic filter was configured under various interfaces on the local router. However, shortly after implementing the traffic filter, OSPFv3 neighbor adjacencies were lost. What caused this issue?
A. The traffic filter is blocking all ICMPv6 traffic.
B. The global anycast address must be added to the traffic filter to allow OSPFv3 to work properly.
C. The link-local addresses that were used by OSPFv3 were explicitly denied, which caused the neighbor relationships to fail.
D. IPv6 traffic filtering can be implemented only on SVIs.
Answer: C
Explanation:
OSPFv3 uses link-local IPv6 addresses for neighbor discovery and other features, so if any IPv6 traffic
filters are implemented be sure to include the link local address so that it is permitted in the filter list.
Reference: http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/5_x/nx- os/unicast/configuration/
guide/l3_cli_nxos/l3_ospfv3.html
Q5. Refer to the exhibit. The DHCP client is unable to receive a DHCP address from the DHCP server. Consider the following output:
hostname RouterB ! interface fastethernet 0/0
ip address 172.31.1.1 255.255.255.0 interface serial 0/0 ip address 10.1.1.1 255.255.255.252
! ip route 172.16.1.0 255.255.255.0 10.1.1.2
Which configuration is required on the Router B fastethernet 0/0 port in order to allow the DHCP client to successfully receive an IP address from the DHCP server?
A. RouterB(config-if)# ip helper-address 172.16.1.2
B. RouterB(config-if)# ip helper-address 172.16.1.1
C. RouterB(config-if)# ip helper-address 172.31.1.1
D. RouterB(config-if)# ip helper-address 255.255.255.255
Answer: A
Explanation:
Q6. Refer to the exhibit.
A network administrator checks this adjacency table on a router. What is a possible cause for the incomplete marking?
A. incomplete ARP information
B. incorrect ACL
C. dynamic routing protocol failure
D. serial link congestion
Answer: A
Explanation:
To display information about the Cisco Express Forwarding adjacency table or the hardware Layer 3-
switching adjacency table, use the show adjacency command.
Reasons for Incomplete Adjacencies
There are two known reasons for an incomplete adjacency:
The router cannot use ARP successfully for the next-hop interface.
After a clear ip arp or a clear adjacency command, the router marks the adjacency as incomplete. Then it
fails to clear the entry.
In an MPLS environment, IP CEF should be enabeled for Label Switching. Interface level command ip
route-cache cef No ARP Entry When CEF cannot locate a valid adjacency for a destination prefix, it punts
the packets to the CPU for ARP resolution and, in turn, for completion of the adjacency.
Reference: http://www.cisco.com/c/en/us/support/docs/ip/express-forwarding-cef/17812-cefincomp.
html#t4
Q7. PPPoE is composed of which two phases?
A. Active Authentication Phase and PPP Session Phase
B. Passive Discovery Phase and PPP Session Phase
C. Active Authorization Phase and PPP Session Phase
D. Active Discovery Phase and PPP Session Phase
Answer: D
Explanation:
PPPoE is composed of two main phases:
Active Discovery Phase--In this phase, the PPPoE client locates a PPPoE server, called an access
concentrator. During this phase, a Session ID is assigned and the PPPoE layer is established.
PPP Session Phase--In this phase, PPP options are negotiated and authentication is performed. Once the
link setup is completed, PPPoE functions as a Layer 2 encapsulation method, allowing data to be transferred over the PPP link within PPPoE headers.
Reference:
http://www.cisco.com/c/en/us/td/docs/security/asa/asa92/configuration/vpn/asa-vpn- cli/vpn-pppoe.html
Topic 3, Layer 3 Technologies
20. Refer to the exhibit.
Which one statement is true?
A. Traffic from the 172.16.0.0/16 network will be blocked by the ACL.
B. The 10.0.0.0/8 network will not be advertised by Router B because the network statement for the 10.0.0.0/8 network is missing from Router B.
C. The 10.0.0.0/8 network will not be in the routing table on Router B.
D. Users on the 10.0.0.0/8 network can successfully ping users on the 192.168.5.0/24 network, but users on the 192.168.5.0/24 cannot successfully ping users on the 10.0.0.0/8 network.
E. Router B will not advertise the 10.0.0.0/8 network because it is blocked by the ACL.
Q8. Which traffic characteristic is the reason that UDP traffic that carries voice and video is assigned to the queue only on a link that is at least 768 kbps?
A. typically is not fragmented
B. typically is fragmented
C. causes windowing
D. causes excessive delays for video traffic
Answer: A
Explanation:
Q9. Which parameter in an SNMPv3 configuration offers authentication and encryption?
A. auth
B. noauth
C. priv
D. secret
Answer: C
Explanation:
Q10. A network engineer is investigating the cause of a service disruption on a network segment and executes the debug condition interface fastethernet f0/0 command. In which situation is the debugging output generated?
A. when packets on the interface are received and the interface is operational
B. when packets on the interface are received and logging buffered is enabled
C. when packets on the interface are received and forwarded to a configured syslog server
D. when packets on the interface are received and the interface is shut down
Answer: A
Explanation: