1.
Refer to the exhibit. The network administrator wants to minimize the number of entries in Router1’s routing
table. What should the administrator implement on the network?
Correct Answer
B. CIDR
Explanation
CIDR (Classless Inter-Domain Routing) should be implemented on the network in order to minimize the number of entries in Router1's routing table. CIDR allows for the aggregation of multiple IP addresses into a single routing table entry, reducing the overall size of the routing table. This is achieved by using variable length subnet masks (VLSM) to allocate IP addresses more efficiently and by grouping IP addresses into smaller, more manageable blocks. By implementing CIDR, the network administrator can effectively reduce the number of entries in Router1's routing table and optimize the network's routing capabilities.
2.
What does VLSM allow a network administrator to do?
Correct Answer
B. Utilize multiple subnet masks in the same IP address space
Explanation
VLSM (Variable Length Subnet Masking) allows a network administrator to utilize multiple subnet masks in the same IP address space. This means that the administrator can divide the IP address space into smaller subnets of different sizes, based on the specific requirements of each subnet. This allows for more efficient utilization of IP addresses and better allocation of network resources. With VLSM, different subnets can have different subnet masks, allowing for more flexibility in network design and addressing.
3.
Refer to the exhibit. A network engineer is summarizing the two groups of routes on router R1 shown in the
exhibit. Which summarization will work for all the subnets?
Correct Answer
C. 192.168.0.0/21
Explanation
The correct answer is 192.168.0.0/21. This is the best summarization because it includes all the subnets listed (192.168.0.0/23, 192.168.0.0/22, 192.168.0.0/21, and 192.168.0.0/20) and provides the most efficient route aggregation. By using a /21 subnet mask, it covers a larger range of addresses and reduces the number of routing entries required.
4.
4A network administrator is tasked with dividing up a class C network among the QA, Sales, and Administration
departments. The QA department is made up of 10 people, the Sales is made up of 28 people, and the
Administration has 6. Which two subnets masks adequately address the QA and Sales departments? (Choose
two.)
Correct Answer(s)
B. 255.255.255.224 for Sales
C. 255.255.255.240 for QA
Explanation
The subnet mask 255.255.255.224 (which provides 30 usable IP addresses) adequately addresses the Sales department, as it has 28 people. The subnet mask 255.255.255.240 (which provides 14 usable IP addresses) adequately addresses the QA department, as it has 10 people.
5.
Which of the following problems does VLSM help to alleviate?
Correct Answer
A. The shortage of IP addresses
Explanation
VLSM (Variable Length Subnet Masking) helps alleviate the shortage of IP addresses. VLSM allows for the allocation of IP addresses in a more efficient manner by assigning smaller subnets to networks that require fewer addresses and larger subnets to networks that require more addresses. This helps conserve IP addresses and make more efficient use of the available address space.
6.
Refer to the exhibit. The network administrator wants to create a subnet for the point-to-point connection
between the two routers. Which subnetwork mask would provide enough addresses for the point-to-point link
with the least number of wasted addresses?
Correct Answer
E. 255.255.255.252
Explanation
The subnet mask 255.255.255.252 provides enough addresses for the point-to-point link with the least number of wasted addresses. This subnet mask allows for 2 usable addresses, which is sufficient for the two routers to communicate with each other. The remaining addresses in the subnet are wasted, but since the requirement is to minimize wasted addresses, this is the best option.
7.
Refer to the exhibit. What subnet mask will be applied by router B when it receives a RIPv1 update for the
network 172.16.1.0?
Correct Answer
D. 24
Explanation
When router B receives a RIPv1 update for the network 172.16.1.0, it will apply a subnet mask of 24. A subnet mask of 24 means that the first 24 bits of the IP address are used to identify the network, while the remaining 8 bits are used to identify the host within that network. This indicates that the network has a Class C IP address, as Class C IP addresses have a default subnet mask of 255.255.255.0, which is equivalent to a subnet mask of 24.
8.
An additional subnet is required for a new Ethernet link between Router1 and Router2 as shown in the diagram.
Which of the following subnet addresses can be configured in this network to provide a maximum of 14 useable
addresses for this link while wasting the fewest addresses?
Correct Answer
E. 192.1.1.224/28
9.
A router has a summary route to network 192.168.32.0/20 installed in its routing table. What range of networks
are summarized by this route?
Correct Answer
C. 192.168.32.0 – 192.168.47.0/24
Explanation
The correct answer is 192.168.32.0 – 192.168.47.0/24. This is because the summary route of 192.168.32.0/20 includes all the networks from 192.168.32.0 to 192.168.47.0, with a subnet mask of /24.
10.
10What two advantages does CIDR provide to a network? (Choose two.)
Correct Answer(s)
A. Reduced routing table size
D. Reduced routing update traffic
Explanation
CIDR, or Classless Inter-Domain Routing, provides two advantages to a network. Firstly, it helps in reducing the size of the routing table by allowing for more efficient allocation of IP addresses. This is achieved by using variable length subnet masks (VLSM) instead of fixed length subnet masks (FLSM). Secondly, CIDR reduces the amount of routing update traffic that is sent across the network. This is because CIDR allows for the aggregation of multiple IP addresses into a single route, reducing the number of individual routes that need to be advertised and updated.
11.
Refer to the exhibit. Which address is a broadcast address for one of the subnets that are shown in the exhibit?
Correct Answer
B. 192.168.4.15/29
Explanation
The given answer, 192.168.4.15/29, is a broadcast address for one of the subnets shown in the exhibit. In a subnet with a /29 prefix, there are 8 IP addresses available. The first address is the network address, the last address is the broadcast address, and the remaining 6 addresses are usable for hosts. Therefore, in the subnet 192.168.4.0/29, the broadcast address would be 192.168.4.7. However, since the question specifies that the broadcast address is one of the subnets shown in the exhibit, the only option that matches this criteria is 192.168.4.15/29.
12.
Refer to the exhibit. The number of required host addresses for each subnet in a network is listed in the exhibit.
This number includes the host address requirements for all router ports and hosts on that subnet. After all
device and router port address assignments are determined, what will be the total number of unused host
addresses available?
Correct Answer
C. 29
13.
15 Which three interior routing protocols support VLSM? (Choose three.)
Correct Answer(s)
A. OSPF
C. RIP v2
D. EIGRP
Explanation
OSPF, RIP v2, and EIGRP are the three interior routing protocols that support VLSM. OSPF (Open Shortest Path First) is a link-state routing protocol that supports VLSM by allowing the use of variable length subnet masks. RIP v2 (Routing Information Protocol version 2) is a distance-vector routing protocol that also supports VLSM by allowing the use of variable length subnet masks. EIGRP (Enhanced Interior Gateway Routing Protocol) is a hybrid routing protocol that supports VLSM by allowing the use of variable length subnet masks.
14.
Which of the following are contained in the routing updates of classless routing protocols? (Choose two.)
Correct Answer(s)
A. 32-bit address
C. Subnet mask
Explanation
The routing updates of classless routing protocols contain the 32-bit address and subnet mask. The 32-bit address is used to identify the network and the subnet mask is used to determine the range of IP addresses within the network. These two pieces of information are essential for the routers to determine the best path for forwarding packets in a classless routing environment.
15.
Refer to the exhibit. A network technician enters the static route in R1 needed to reach network 10.1.1.0/24. A
ping from R1 to Host B fails. The technician begins testing the network and has the following results:
1. pings from R1 to the S0/0/0 interface on R2....successful
2. pings from R1 to the Fa0/0 interface on R2....successful
3. pings from Host B to hosts on the 10.1.1.0/24 network....successful
4. pings from Host B to the Fa0/0 interface on R2....successful
5. pings from R2 to Host B....successful
What is the likely cause of the failure of the ping from R1 to Host B?
Correct Answer
B. The default gateway on Host B is not correctly set.
Explanation
The likely cause of the failure of the ping from R1 to Host B is that the default gateway on Host B is not correctly set. This is indicated by the successful pings from R1 to the S0/0/0 and Fa0/0 interfaces on R2, as well as the successful pings from Host B to hosts on the 10.1.1.0/24 network and the Fa0/0 interface on R2. Additionally, the successful ping from R2 to Host B suggests that there is no Layer 2 problem between R2 and Host B. Therefore, the most probable cause is an incorrect default gateway setting on Host B.
16.
Refer to the exhibit. A network administrator needs to create two subnetworks from 10.0.0.0/8 for a router
running RIPv2. The Admin subnet requires 120 hosts and the Sales subnet requires 58 hosts. The network
administrator assigned 10.0.1.128/25 to the Admin subnet. The Sales subnet is given 10.0.1.192/26. What will
be the result of this addressing scheme?
Correct Answer
C. The subnets overlap and will be rejected by the router.
Explanation
The given addressing scheme will result in overlapping subnets, which will be rejected by the router. This is because both the Admin and Sales subnets have been assigned IP addresses from the same network range (10.0.1.0/24). As a result, when the router tries to route packets between these subnets, it will encounter conflicts due to the overlapping IP addresses. Therefore, the router will reject this addressing scheme.
17.
Refer to the exhibit. In the network that is shown, the router interfaces are assigned the first address in each
subnet. Which IP address would be usable for a host on one of the LANs in this network?
Correct Answer
D. 192.168.2.130/25
Explanation
The given IP address 192.168.2.130/25 would be usable for a host on one of the LANs in this network. This is because the subnet mask /25 allows for 126 host addresses, and the host address 192.168.2.130 falls within this range.
18.
What is a supernet?
Correct Answer
D. A summarization of serveral IP classful networks into one IP address range
Explanation
A supernet is a summarization of several IP classful networks into one IP address range. This means that multiple smaller networks are combined into a larger network, allowing for more efficient routing and address allocation. By using a supernet, it is possible to reduce the number of routing table entries and conserve IP addresses.