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Q1. In the DiffServ model, which class represents the highest priority with the highest drop probability?
A. AF11
B. AF13
C. AF41
D. AF43
Answer: D
Explanation:
AF43 — Assured forwarding, high drop probability, Class 4 DSCP, and Flash-override precedence.
Table of AF Classes and Drop Priority
Drop Precedence
Class 1
Class 2
Class 3
Class 4
Low drop
AF11
DSCP 10
001010
AF21
DSCP 18
010010
AF31
DSCP 26
011010
AF41
DSCP 34
100010
Medium drop
AF12
DSCP 12
001100
AF22
DSCP 20
010100
AF32
DSCP 28
011100
AF42
DSCP 36
100100
High drop
AF13
DSCP 14
001110
AF23
DSCP 22
010110
AF33
DSCP 30
011110
AF43
DSCP 38
100110
Reference:
https://www.informit.com/library/content.aspx?b=CCIE_Practical_Studies_II&seqNum=56
Q2. Which two statements about the client-identifier in a DHCP pool are true? (Choose two.)
A. It specifies a unique identifier that is used only for DHCP requests.
B. It is specified by appending 01 to the MAC address of a DHCP client.
C. It specifies a hardware address for the client.
D. It specifies a unique identifier that is used only for BOOTP requests.
E. It requires that you specify the hardware protocol.
Answer: A,B
Reference:
client-identifier unique-identifier
Example:
Device(dhcp-config)# client-identifier 01b7.0813.8811.66
Specifies the unique identifier for DHCP clients.
This command is used for DHCP requests.
DHCP clients require client identifiers. You can specify the unique identifier for the client in either of the following ways:
A 7-byte dotted hexadecimal notation. For example, 01b7.0813.8811.66, where 01 represents the Ethernet media type and the remaining bytes represent the MAC address of the DHCP client.
A 27-byte dotted hexadecimal notation. For example, 7665.6e64.6f72.2d30.3032.342e.3937.6230.2e33.3734.312d.4661.302f.31. The equivalent ASCII string for this hexadecimal value is vendor-0024.97b0.3741-fa0/1, where vendor represents the vendor, 0024.97b0.3741 represents the MAC address of the source interface, and fa0/1 represents the source interface of the DHCP client.
See the Troubleshooting Tips section for information about how to determine the client identifier of the DHCP client.
Note
The identifier specified here is considered for a DHCP client that sends a client identifier in the packet.
Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_dhcp/configuration/15-mt/dhcp-15-mt-book/config-dhcp-server.html
Q3. Refer to the exhibit.
Why is the neighbor relationship between R2 and R4 shown as ES-IS?
A. because there is an MTU mismatch between R2 and R4
B. because interface S3/0 of R4 is configured as L1/L2
C. because interface S3/0 of R2 is configured as L1
D. because there is a hello interval mismatch between R2 and R4
Answer: C
Explanation:
With IS-IS we will see ES-IS when one of the following is true:
. uk.co.certification.simulator.questionpool.PList@138b7160
So in this question because we do not know about the other side’s “show CLNS neighbor” A must be the better choose.
Q4. Which two loop-prevention mechanisms are implemented in BGP? (Choose two.)
A. A route with its own AS in the AS_PATH is dropped automatically if the route reenters its own AS.
B. A route with its own cluster ID in the CLUSTER_LIST is dropped automatically when the route reenters its own AS.
C. The command bgp allowas-in enables a route with its own AS_PATH to be dropped when it reenters its own AS.
D. The command bgp bestpath as-path ignore enables the strict checking of AS_PATH so that they drop routes with their own AS in the AS_PATH.
E. The command bgp bestpath med missing-as-worst assigns the smallest possible MED, which directly prevents a loop.
Answer: A,B
Explanation:
When dealing with the possibility of routing updates making their way back into an AS, BGP relies on the information in the AS_path for loop detection. An update that tries to make its way back into the AS it was originated from will be dropped by the border router. With the introduction of route reflectors, there is a potential for having routing loops within an AS. A routing update that leaves a cluster might find its way back inside the cluster. Loops inside the AS cannot be detected by the traditional AS_path approach because the routing updates have not left the AS yet. BGP offers two extra measures for loop avoidance inside an AS when route reflectors are configured.
Using an Originator ID
The originator ID is a 4-byte, optional, nontransitive BGP attribute (type code 9) that is created by the route reflector. This attribute carries the router ID of the originator of the route in the local AS. If, because of poor configuration, the update comes back to the originator, the originator ignores it.
Using a Cluster List
The cluster list is an optional, nontransitive BGP attribute (type code 10). Each cluster is represented with a cluster ID.
A cluster list is a sequence of cluster IDs that an update has traversed. When a route reflector sends a route from its clients to nonclients outside the cluster, it appends the local cluster ID to the cluster list. If the route reflector receives an update whose cluster list contains the local cluster ID, the update is ignored. This is basically the same concept as the AS_path list applied between the clusters inside the AS.
Reference: http://borg.uu3.net/cisco/inter_arch/page11.html
Q5. DRAG DROP
Drag each IS-IS command on the left to its effect on the right.
Answer:
Q6. Which standard feature can be exploited by an attacker to perform network reconnaissance?
A. IP-directed broadcast
B. maintenance operations protocol
C. ICMP redirects
D. source quench
Answer: C
Q7. Which LSA type is associated with the default route in a totally stubby area?
A. interarea-prefix LSA for ABRs (Type 3)
B. autonomous system external LSA (Type 5)
C. router LSA (Type 1)
D. interarea-router LSAs for ASBRs (Type 4)
Answer: A
Q8. Which command sets the maximum segment size for a TCP packet initiated from a router?
A. ip mtu
B. ip tcp adjust-mss
C. ip tcp mss
D. ip tcp window-size
Answer: C
Q9. Refer to the exhibit.
Which statement about configuring the switch to manage traffic is true?
A. The switchport priority extend cos command on interface FastEthernet0/0 prevents traffic to and from the PC from taking advantage of the high-priority data queue that is assigned to the IP phone.
B. The switchport priority extend cos command on interface FastEthernet0/0 enables traffic to and from the PC to use the high priority data queue that is assigned to the IP phone.
C. When the switch is configured to trust the CoS label of incoming traffic, the trusted boundary feature is disabled automatically.
D. The mls qos cos override command on interface FastEthernet0/0 configures the port to trust the CoS label of traffic to and from the PC.
Answer: A
Explanation:
In some situations, you can prevent a PC connected to the Cisco IP Phone from taking advantage of a high-priority data queue. You can use the switchport priority extend cos interface configuration command to configure the telephone through the switch CLI to override the priority of the traffic received from the PC.
Reference: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2950/software/release/12-1_22_ea2/configuration/guide/2950scg/swqos.html
Q10. Which statement about OSPF loop prevention is true?
A. The discard route is generated automatically on the ABR to prevent routing loops.
B. The ASBR uses type 3 LSAs from non-backbone areas to prevent control-plane routing loops.
C. The ABR can filter type 3 LSPs to prevent routing loops.
D. The DN bit ignores LSA types 2, 3, and 5 to prevent routing loops.
Answer: A