Quiz: Networking (Routing & Switching)

  1. The following matters were not addressed specifically in the text. However, if you understand the concepts of Layer 1 and Layer 2 standards, in each case, give your answer and explain your reasoning. 

    a) Is multipath interference a Layer 1 or Layer 2 concern?

Because Layer 1 deals with the connection between devices, the multipath interface is Layer 1 concern.

b) Is media access control a Layer 1 or Layer 2 concern?

Because Layer 2 deals with switch operations and frame formats Media Access Control falls under the responsibility of Layer 2. When the Host and Access points will transmit is overseen by Mac methods.

c) Is MIMO a Layer 1 or Layer 2 concern?

To improve communication performance both receiver and transmitter use multiple antennas, which is MIMO basically and that’s also the responsibility of Layer 1.

d) Is 802.11ac a Layer 1 or Layer 2 standard?

Wireless propagation is a Layer 2 concern. Since it guarantees medium access, and synchronization and control error between two elements. With wireless networks, this regularly includes coordination of access to the normal air medium and recovery from mistakes that may happen in the data as it engenders from source to destination.

e) Is 802.11r a Layer 1 or Layer 2 standard?

This is additionally Wireless spread so its Layer 2 worry as Most wireless network sorts has a typical technique for performing data connect layer capacities autonomous of the genuine method for transmission.

 

  1. Create a policy for 802.11 Wi-Fi security in a 10-person company with a single access point WLAN. You can write the policy as a series of rules that both administrators and employees should read and follow. Use complete sentences. Do not go beyond the recommendations stated in the textbook

To secure wireless technologies the 10-worker organization, what you ought to do is to give cryptographic assurance between the wireless access point and the wireless host which incorporates beginning confirmation in addition to message-by-message privacy, trustworthiness, and validation so programmers can’t capture movement or send his or her own particular messages to the access point; kill the occasional telecom of the access point’s SSID; acknowledge just PCs whose wireless network interface cards have pre-affirmed EUI address.

A clarification of the security arrangement for the 10-worker organization is not the same as an independent venture/home office environment:

As a matter of first importance, there is a major contrast: independent companies or homes network with a solitary access point that utilization 802.11i mode, substantial firms, for example, the 10-worker organization with many access points utilize an 802.1X mode to keep aggressors from essentially strolling into a building and connecting a PC to any divider jack or straightforwardly into a switch.

Moreover, there are contrasts between independent ventures/homes network and organizations. For instance, home doesn’t utilize a focal confirmation serve while organizations do; Homes utilize Knowledge of a pre-shared key for verification while Companies utilize Credentials on focal validation server; Homes utilizeTechnologically solid, however, powerless human security can bargain the mechanical security while organizations utilize the to a great degree solid security. In a home or independent venture, having a modest bunch of individuals know the pre-shared key is not very hazardous. Interestingly, there are potential perils that somebody in an independent venture, excusing that everybody knows the pre-session key, will offer it to an unapproved individual

To shield from the vulnerabilities and dangers from shrewdness twin, don’t join open WiFi with the powerful access point. Given that the wireless host is arranged to pick the most elevated power access point, it will take up with the abhorrent twin access point rather than the true blue access point. It will set up a safe 802.11i connection with the wireless victim customer.

 

  1. Answer the following questions about IP addresses.a) How do you find the network address from a listed IP address?

From the Subnet Mask of the IP address. There are many ways to find it but having Subnet is necessary. e.g.

IP:        171.17.171.17

Subnet: 255.255. 0. 0

Net ID: 171.17.0.0

b) What is the valid range of a Class C network address?

Answer:

192-223

c) What is the Class B private IP address space (from the first address to the last address)?

Answer:

1st: 172.16.0.0/12

Last: 172.31.0.0/12

d) How many subnets and hosts per subnet can you get from the network 172.27.0.0 with a subnet mask of 255.255.255.0?

Answer: 16/16

 

4. Shown below is the content of a routing table. Use the 3-step matching rules to find the next-hop router for arriving packets with the following destination IP addresses. For each forwarding decision, explain your reasoning.

 

Arriving Packet 1:        64.28.197.250

Arriving packet 2:         140.186.35.138

Arriving Packet 3:        196.230.90.31

Arriving Packet 4:        120.75.63.26

Routing Table

Row Destination Mask Metric (Hop Next-Hop
Network Count) Router
1 120.15.179.0 255.255.255.0 (/24) Local
2 140.186.35.0 255.255.255.0 (/24) 6 D
3 174.16.9.0 255.255.255.0 (/24) 8 A
4 68.5.44.0 255.255.255.0 (/24) 5 C
5 64.0.0.0 255.0.0.0 (/8) 3 A
6 140.186.35.0 255.255.255.0 (/24) 8 A
7 197.14.0.0 255.255.0.0 (/16) 2 C
8 64.28.0.0 255.255.0.0 (/16) 4 B
9 120.75.63.0 255.255.255.0 (/24) 9 B
10 196.5.0.0 255.255.255.0 (/16) 6 A
11 196.230.89.0 255.255.255.0 (/24) 9 C
12 120.75.63.0 255.255.255.0 (/24) 8 A
13 196.230.91.0 255.255.255.0 (/24) 10 C
14 201.5.5.0 255.255.255.0 (/24) 7 C
15 0.0.0.0 0.0.0.0 (/0) D

 

Note:

  • The outgoing router interface column is omitted from the table.
  • Row 15 shows the default route.

 

Packet 1: Row 8 Router B (NextHopRouter)

Packet 2: Row 2 Router D (NextHopRouter)

Packet 3: Row 11 Router C (NextHopRouter)

Packet 4: Row 12 Router A (NextHopRouter)

  1. Determine IP and MAC header information for a data packet.

IP Address MAC Address
Client A 142.18.5.10 AB:CD:EF:EF:CD:AB
Server B 175. 23.9.17 56:78:90:AB:CD:EF
R1 Interface E0 142.18.5.11 DA:EB:FC:CF:BE:AD
R1 Interface E1 24.57.27.62 11:22:33:AA:BB:CC
R2 Interface F0 24.57.27.63 FB:CD:EA:DC:BF:AE
R2 Interface F1 172. 23.9.11 99:88:77:66:55:44

 

the configuration in the figure above shows three networks interconnected through two routers. Client A is sending a data packet to Server B. At the data link layer, the packet is encapsulated in a frame on each of the three networks.

 

Record the destination/source MAC addresses and IP addresses for the frame/packet transmitted from Client A to interface E0 of R1.

 

Frame Header IP Packet Header Data
Destination Source Destination Source Hello!
11:22:33:AA:BB:CC AB:CD:EF:EF:CD:AB 142.18.5.11 142.18.5.10
Frame/Packet from Client A to interface E0 of R1

 

 

Record the destination/source MAC addresses and IP addresses for the frame/packet transmitted from interface E1 of R1 to interface F0 of R2.

 

Frame Header IP Packet Header Data
Destination Source Destination Source Hello!
FB:CD:EA:DC:BF:AE 11:22:33:AA:BB:CC 24.57.27.63 24.57.27.62
     
Frame/Packet from interface E1 of R1 to Interface F0 of R2

 

 

Record the destination/source MAC addresses and IP addresses for the frame/packet transmitted from interface F1 of R2 to Server B.

 

Frame Header IP Packet Header Data
Destination Source Destination Source Hello!
56:78:90:AB:CD:EF 99:88:77:66:55:44 175. 23.9.17 99:88:77:66:55:44
       
Frame/Packet from interface F1 of R2 to Server B

 

 

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