Q1. - (Topic 7)
Which component of the routing table ranks routing protocols according to their preferences?
A. administrative distance
B. next hop
C. metric
D. routing protocol code
Answer: A
Explanation:
Administrative distance - This is the measure of trustworthiness of the source of the
route. If a router learns about a destination from more than one routing protocol,
administrative distance is compared and the preference is given to the routes with lower
administrative distance. In other words, it is the believability of the source of the route.
Q2. - (Topic 7)
Which destination IP address can a host use to send one message to multiple devices across different subnets?
A. 172.20.1.0
B. 127.0.0.1
C. 192.168.0.119
D. 239.255.0.1
Answer: D
Explanation: Multicast is a networking protocol where one host can send a message to a special multicast IP address and one or more network devices can listen for and receive
those messages. Multicast works by taking advantage of the existing IPv4 networking infrastructure, and it does so in something of a weird fashion. As you read, keep in mind that things are a little confusing because multicast was "shoe-horned" in to an existing technology. For the rest of this article, let's use the multicast IP address of 239.255.0.1. We'll not worry about port numbers yet, but make a mental note that they are used in multicast. We'll discuss that later.
Q3. - (Topic 3)
The internetwork infrastructure of company XYZ consists of a single OSPF area as shown in the graphic. There is concern that a lack of router resources is impeding internetwork performance. As part of examining the router resources, the OSPF DRs need to be known. All the router OSPF priorities are at the default and the router IDs are shown with each router.
Which routers are likely to have been elected as DR? (Choose two.)
A. Corp-1
B. Corp-2
C. Corp-3
D. Corp-4
E. Branch-1
F. Branch-2
Answer: D,F
Explanation:
There are 2 segments on the topology above which are separated by Corp-3 router. Each
segment will have a DR so we have 2 DRs.
To select which router will become DR they will compare their router-IDs. The router with
highest (best) router-ID will become DR. The router-ID is chosen in the order below:
+
The highest IP address assigned to a loopback (logical) interface.
+
If a loopback interface is not defined, the highest IP address of all active router’s physical interfaces will be chosen.
In this question, the IP addresses of loopback interfaces are not mentioned so we will consider IP addresses of all active router’s physical interfaces. Router Corp-4 (10.1.40.40)
& Branch-2 (10.2.20.20) have highest “active” IP addresses so they will become DRs.
Q4. - (Topic 1)
To what type of port would a cable with a DB-60 connector attach?
A. Serial port
B. Console port
C. Ethernet port
D. Fibre optic port
Answer: A
Explanation:
Serial Connection
cl_3_dte_male
cl_2_dce
The picture on the left shows a V.35 DTE cable with a male DB60 connector and a male standard 34-pin Winchester-type connector. The right picture shows a V.35 DCE serial cable with a male DB60 connector and a female 34-pin Winchester-type connector. As you probably guessed already, the male connector of the DTE cable is attached to the DCE cable's female connector, this is depicted in the picture below. This is known as a back-to-back connection, and 'simulates' a WAN link. In a real world setup, the DTE cable's male connector typically connects to a port on a CSU/DSU provided by a service provider (i.e. telco), which in turn connects to a CSU/DSU at another location, thru a T1 link for example.
The DB60 connector connects to a Serial interface on a router.
cl_4_malefemale Reference: http://www.techexams.net/techlabs/ccna/lab_hardware.shtml
Q5. - (Topic 3)
Which statement is true?
A. An IPv6 address is 64 bits long and is represented as hexadecimal characters.
B. An IPv6 address is 32 bits long and is represented as decimal digits.
C. An IPv6 address is 128 bits long and is represented as decimal digits.
D. An IPv6 address is 128 bits long and is represented as hexadecimal characters.
Answer: D
Explanation:
http://www.cisco.com/en/US/technologies/tk648/tk872/technologies_white_paper0900aecd 8026003d.pdf
One of the key advantages IPv6 brings is the exponentially larger address space. The following will outline the basic address architecture of IPv6. 128-bit-long addresses Represented in hexadecimal format: Uses CIDR principles: prefix/prefix length x:x:x:x:x:x:x:x, where x is a 16-bit hex field The last 64 bits are used for the interface ID
Q6. - (Topic 7)
On which type of device is every port in the same collision domain?
A. a router B. a Layer 2 switch
C. a hub
Answer: C
Explanation: Collision domainA collision domain is, as the name implies, a part of a network where packet collisions can occur. A collision occurs when two devices send a packet at the same time on the shared network segment. The packets collide and both devices must send the packets again, which reduces network efficiency. Collisions are often in a hub environment, because each port on a hub is in the same collision domain. By contrast, each port on a bridge, a switch or a router is in a separate collision domain.
Q7. - (Topic 1)
Which two characteristics apply to Layer 2 switches? (Choose two.)
A. Increases the number of collision domains
B. Decreases the number of collision domains
C. Implements VLAN
D. Decreases the number of broadcast domains
E. Uses the IP address to make decisions for forwarding data packets
Answer: A,C
Explanation:
Layer 2 switches offer a number of benefits to hubs, such as the use of VLANs and each switch port is in its own separate collision domain, thus eliminating collisions on the segment.
Q8. - (Topic 1)
How does TCP differ from UDP? (Choose two.)
A. TCP provides best effort delivery.
B. TCP provides synchronized communication.
C. TCP segments are essentially datagrams.
D. TCP provides sequence numbering of packets.
E. TCP uses broadcast delivery.
Answer: B,D
Explanation:
Because TCP is a connection-oriented protocol responsible for ensuring the transfer of a datagram from the source to destination machine (end-to-end communications), TCP must receive communications messages from the destination machine to acknowledge receipt of the datagram. The term virtual circuit is usually used to refer to the handshaking that goes on between the two end machines, most of which are simple acknowledgment messages (either confirmation of receipt or a failure code) and datagram sequence numbers. Rather than impose a state within the network to support the connection, TCP uses synchronized state between the two endpoints. This synchronized state is set up as part of an initial connection process, so TCP can be regarded as a connection-oriented protocol. Much of the protocol design is intended to ensure that each local state transition is communicated to, and acknowledged by, the remote party.
Reference: http://en.wikibooks.org/wiki/Communication_Networks/TCP_and_UDP_Protocols
Q9. - (Topic 3)
Refer to the exhibit.
Assume that all router interfaces are operational and correctly configured. In addition, assume that OSPF has been correctly configured on router R2. How will the default route configured on R1 affect the operation of R2?
A. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately.
B. Any packet destined for a network that is not referenced in the routing table of router R2 will be directed to R1. R1 will then send that packet back to R2 and a routing loop will occur.
C. Any packet destined for a network that is not directly connected to router R1 will be dropped.
D. The networks directly connected to router R2 will not be able to communicate with the 172.16.100.0, 172.16.100.128, and 172.16.100.64 subnetworks.
E. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately because of the lack of a gateway on R1.
Answer: B
Explanation:
First, notice that the more-specific routes will always be favored over less-specific routes regardless of the administrative distance set for a protocol. In this case, because we use OSPF for three networks (172.16.100.0 0.0.0.3, 172.16.100.64 0.0.0.63, 172.16.100.128 0.0.0.31) so the packets destined for these networks will not be affected by the default route. The default route configured on R1 “ip route 0.0.0.0 0.0.0.0 serial0/0 will send any packet whose destination network is not referenced in the routing table of router R1 to R2, it doesn’t drop anything. These routes are declared in R1 and the question says that “OSPF has been correctly configured on router R2, so network directly connected to router R2 can communicate with those three subnetworks. As said above, the default route configured on R1 will send any packet destined for a network that is not referenced in its routing table to R2; R2 in turn sends it to R1 because it is the only way and a routing loop will occur.
Q10. - (Topic 4)
In the configuration of NAT, what does the keyword overload signify?
A. When bandwidth is insufficient, some hosts will not be allowed to access network translation.
B. The pool of IP addresses has been exhausted.
C. Multiple internal hosts will use one IP address to access external network resources.
D. If the number of available IP addresses is exceeded, excess traffic will use the specified address pool.
Answer: C
Explanation:
The keyword overload.used in the ip nat inside source list 1 pool ovrld overload example command allows NAT to translate multiple inside devices to the single address in the pool. The types of NAT include: Static address translation (static NAT)—Allows one-to-one mapping between local and global addresses. Dynamic address translation (dynamic NAT)—Maps unregistered IP addresses to registered IP addresses from a pool of registered IP addresses. Overloading—Maps multiple unregistered IP addresses to a single registered IP address (many to one) using different ports. This method is also known as Port Address Translation (PAT). By using overloading, thousands of users can be connected to the Internet by using only one real global IP address.