4.4 La biorremediación
4.4.3 Biodepuración del aire con plantas vegetales
QUESTION NO: 1
Part of the TestKing network is shown below:
You work as a network technician for TestKing and are responsible for this network. Based on the diagram shown above, how many collision domains are there? A. Six B. Fourteen C. Four D. Two E. Three F. One G. Eight
Answer: D Explanation:
The multi-segment configuration guidelines apply only to a single Ethernet "collision domain." A collision domain is formally defined as a single CSMA/CD network in which there will be a collision if two computers attached to the system transmit at the same time. An Ethernet system composed of a single segment or multiple segments linked with repeaters is a network that functions as a single collision domain.
FIGURE 1 Repeater hubs create a single collision domain
The figure shows two repeater hubs connecting three computers. Since only repeater connections are used between segments in this network, all of the segments and computers are in the same collision domain.
In the next figure, the repeaters and DTEs are instead separated by a router (packet switch) and are therefore in separate collision domains, since routers do not forward collision signals from one segment to another. Routers contain multiple Ethernet
interfaces and are designed to receive a packet on one Ethernet port and transmit the data onto another Ethernet port in a new packet.
FIGURE 2 Routers creates separate collision domains
Instead of propagating collision signals between Ethernet segments, routers interrupt the collision domain and allow the Ethernets they link to operate independently. Therefore, you can use packet switching hubs to build larger network systems by interconnecting individual Ethernet systems.
QUESTION NO: 2
You work as a network technician at TestKing.com. You have been assigned the task of designing a new TestKing internetwork. The main priority is to achieve the highest reliability available. TestKing.com is willing to spend more dollars to avoid downtime caused by link failure.
A. Design TestKingA B. Design TestKingB C. Design TestKingC D. Design TestKingD Answer: A Explanation:
A network topology that is set up so that each device is directly connected to every other device on the network. This connection method has built-in redundancy. If one link goes down, the device will transmit via another link.
Example: If the partial mesh design is a compromise between the network administrators and managers, then the full mesh design implies that the network administrators won. This design is every Cisco network administrator's picture of perfection over a Frame Relay cloud. It gives every site a direct virtual circuit to every other site, as shown in Figure This design gives maximum redundancy and minimum packet latency (latency describes how long it takes a packet to reach each location).
QUESTION NO: 3
You work as a network technician at TestKing.com. You have been assigned the task of designing a new TestKing internetwork. The main priority is the achieve the highest reliability available, however not at all costs. TestKing.com is willing to spend more dollars to avoid downtime caused by link failure.
Which of the following four designs would provide some redundancy and increase reliability for all four sites, but would cost less than a fully redundant topology?
A. Design TestKingA B. Design TestKingB C. Design TestKingC D. Design TestKingD Answer: B Explanation:
Example:
QUESTION NO: 4
You work as a network technician at TestKing.com. You have been assigned the task of designing a new TestKing internetwork. The main priority is to minimize the link costs. TestKing.at the same time wants to ensure the branch offices with direct connectity to the main site.
A. Design TestKingA B. Design TestKingB C. Design TestKingC D. Design TestKingD Answer: C Explanation: Every
network looks for cost efficiency. Redundancy is often sacrificed on the altar of monthly cost. Thus, the hub and spoke Frame Relay network design is one of the more common. In this configuration, you pick a centralized location (most likely, your largest, most connected office) as the "hub" of the network. All other locations are considered "spokes" and have a single virtual circuit connection back to the hub.
The major advantage of this configuration is the cost. It offers the cheapest monthly price tag, which cost-cutting corporations enjoy. The disadvantages are beginning to mount against this design, however. The redundancy is sorely lacking. If a single router (the central router) loses connectivity for any reason (if the router crashes, if a trenching company cuts through the line), your entire WAN goes down. The other disadvantage of this design is beginning to eclipse even redundancy. It is the disadvantage of tandem switching. Any time the spoke offices need to reach each other, they must go through the hub office.
Example:
QUESTION NO: 5
The routers in this network are running RIPv2. Which addressing scheme would satisfy the needs of this network yet waste the fewest addresses?
A. Network 1: 192.168.10.0/26Network 2: 192.168.10.64/26Network 3: 192.168.10.128/26Serial link 1: 192.168.20.0/24Serial link 2: 192.168.30.0/24 B. Network 1: 192.168.10.0/26Network 2: 192.168.10.64/28Network 3:
192.168.10.80/29Serial link 1: 192.168.10.88/30Serial link 2: 192.168.10.96/30 C. Network 1: 192.168.10.0/26Network 2: 192.168.10.64/27Network 3:
192.168.10.96/28Serial link 1: 192.168.10.112/30Serial link 2: 192.168.10.116/30 D. Network 1: 192.168.10.0/27Network 2: 192.168.10.64/28Network 3:
192.168.10.96/29Serial link 1: 192.168.10.112/30Serial link 2: 192.168.10.116/30
Answer: C Explanation:
Network 1
Required Number of hosts :50
When We use the 26 bits for Network : 11111111.11111111.11111111.11000000 so 62 usable host can be in one network. 50 host for now and remaining hosts address for further growth.
Network 2
When we use the 27 bits for Network: 11111111.11111111.1111111.11100000 so 30 usable hosts can be in one network.
Network 3
Required Number of Hosts: 10
When we use the 28 bits for Network: 11111111.11111111.11111111.11110000 so 14 usable hosts can be in one network.
Connection between TK1, TK2 and TK3 is WAN so when you use 30 bits network IP, you will not lose any IP addresses from network since this subnet allows for only 2 host addresses.
QUESTION NO: 6
The Testking network is shown below:
A technician is investigating a problem with the network shown above. These symptoms have been observed:
1.All of the user hosts can access the Internet.
2.None of the user hosts can access the server in VLAN9
What could cause the symptoms?
A. Interface S0/0 on the router is down. B. Interface Fa0/1 on the router is down. C. Interface Fa0/5 on Testking3 is down. D. Interface Fa0/4 on Testking3 is down. E. Testking2 is turned off.
F. Trunking is not enabled on the link between Testking1 and Testking3.
Answer: D Explanation:
Since all user hosts have access to internet, link to router has to be up. Therefore, router interface (Fa0/1 - believe it is labeled incorrectly on diagram as Fa1/0) must be up. Since all hosts can ping each other, but none can get to VLAN 9 which is through single interface Fa0/4, this interface must be down.
Choice A: incorrect, S0/0 must be up if internet access available.
Choice B: incorrect, Fa0/1 must be up if internet access (through router) available. Choice C: incorrect, would not prevent access to VLAN9 via other routes (i.e Fa0/7, Fa0/9, Fa0/4)
Choice D: correct
Choice E: incorrect: TestKing2 must be up if internet access (through switch and then router) available
Choice F: incorrect: Disabled trunking on link between TestKing1 and TestKing3 would not prevent access to VLAN9 via other routes
QUESTION NO: 7
What symbol represents a type of device that is connected to interface FastEthemet 0/23 of the 2960 switch Sw1-2960? A. Picture A B. Picture B C. Picture C D. Picture D Answer: D Explanation:
Some of the common Cisco symbols are shown below:
Note: Choice B in this question represents an ATM switch, which is not pictured above. From the output shown in this question, we can see that there a numerous different MAC addresses associated with port Fa 0/23. This can only mean that a device with multiple hosts attached to it is plugged into this port, such as a hub or another switch.