COIT12206 TCP/IP Principles and Protocols Management

a) Construct the classful routing tables for HQ router

HQ Router receives a packet with destination address 192.168.5.10. Answer the following questions based on the network. Show the detailed process, with relevant calculations and conversions, of how the packet is forwarded by HQ Router.

a) Can the data be encapsulated in one frame? If not, how many frames need to besent?

b) What is the size of data in each frame?

a) Write router commands to configure this DHCP server in R1.

b) Explain use of each commands from.

Part A

Question 1 (a)

File Transfer Protocol establishes two separate TCP connection between the client and the server using the two modes that are active mode and passive mode, for transferring the commands and data through the two different channels. Active Mode establishes command channel from the client to the server and the passive mode establishes the data channel from the server to the client.

Question 1 (b)

Anonymous IP addresses are the nodes of the network that are unknown to the server. In addition, the anonymous user also might be an attacker who will be allowed easily to manipulate the system. Therefore, there should be anonymous restriction.

A malicious user can easily implement tools to guess the password of the server using wildcards and also could upload huge amount of data to the server to make the system down or may replace the existing files with the same name that will cause harm to other nodes as well when they try to access the file.

Question 2

IP header contains various fields storing information about the data that are about the source IP of the packet, destination IP of the packet, the TTL or time to live that define the time the packets will be online and many more.

When a packet is transferred from one one end to another end it requires to travel through various routers to reach the final destination. Therefore, while one packet is generated at the source location, the IP header is created with the above-mentioned information. No, while the packet travels through the routers the IP headers are requires to be modified because of presence of several nodes on the route. When the first time packet reaches to the router at that time, the IP header contains source IP as the end user’s IP and destination IP as the router’s IP. Again, when the router forwards that packet to the next hop or the next router/node, the IP header changes its source IP as the router’s IP and destination IP as the IP of the next hope or the next node.

Another field is the TTL or Time to Live when the packet is generated it assigns a time limit for which the packet will remain alive. Now, when the packet travels through router it reduces by 1 every time. When the TTL reduces to zero or 0 then the packet dies automatically and this ensures that the packet is no more on the channel.

Question 3

UDP or User Datagram Protocol is a layer 4 protocol while IP or Internet Protocol is the layer 3 protocol of the TCP/IP model. They serves for different purposes thus they are not directly equivalent for any comparison regarding their reliability. UDP is the protocol that transmits data without establishing a serious connection with the other end it generally does not bother about if the data reaches the other end or not. While, TCP another layer 4 protocol first establishes a secure connection with the other end and after receiving the acknowledgement it starts transmitting the data. Therefore, TCP is considered reliable while UDP is considered unreliable. In addition, IP, the layer three protocol encapsulates the datagram sent down by the layer 4 protocols UDP or TCP, where it adds its own additional information regarding the source and destination and forwards the packet to the destination node. Now, the case is that the reliability of delivery of packet does not depend on the IP but it depends on the UDP and TCP protocols. Therefore, the protocols UDP and IP are not unreliable at the same degree.

Part B

Question 1 (a)

Question 1 (b)

Question 1 (c)

The given IP block is 132.34.12.0/23 when it is converted into binary it becomes 10000110.00100010.0000110|0.00000000/23 where the first 23 bits are the network bits and the rest 9 bits are host bits.

Three sub networks are required to form out of this IP block with having 120, 100 and 60 hosts respectively. The sub netting acquires host bits to act as the network bits. Borrowing 1 bit from the host Part will make 2¹ or 2 sub networks while borrowing 2 bits will make 2² or 4 sub networks. In this case, 120 hosts are required in the first sub network therefore, 2⁷ or 128 IPs or 7 bits are assigned to the host Part and 25 bits are assigned to the network Part.

Subnet A:

Network Address: 10000110.00100010.00001100.0|0000000/25 or 134.34.12.0/25

Broadcast address: 10000110.00100010.00001100.0|1111111 or 134.34.12.127

(The network bits will remain same and host bits will be all on.)

Subnet Mask: 11111111.11111111.11111111.1|0000000 or 255.255.255.128

(The networks bit will be all on and host bits will be all off)

First IP: 134.34.12.1 (The next IP of the network address)

Last IP: 134.34.12.126 (The previous IP of the broadcast Address)

Subnet B:

Network Address: 10000110.00100010.00001100.1|0000000/25 or 134.34.12.128/25

Broadcast address: 10000110.00100010.00001100.1|1111111 or 134.34.12.255

(The network bits will remain same and host bits will be all on.)

Subnet Mask: 11111111.11111111.11111111.1|0000000 or 255.255.255.128

(The networks bit will be all on and host bits will be all off)

First IP: 134.34.12.129 (The next IP of the network address)

Last IP: 134.34.12.254 (The previous IP of the broadcast Address)

Subnet C:

Network Address: 10000110.00100010.00001101.00|000000/26 or 134.34.13.0/26

Broadcast address: 10000110.00100010.00001101.00|111111 or 134.34.13.63

(The network bits will remain same and host bits will be all on.)

Subnet Mask: 11111111.11111111.11111111.11|000000 or 255.255.255.192

(The networks bit will be all on and host bits will be all off)

First IP: 134.34.13.1 (The next IP of the network address)

Last IP: 134.34.13.62 (The previous IP of the broadcast Address)

Question 2 (a)

Question 2 (b)

When the router receives a packet having destination of 192.168.5.10 it modifies the IP header of the packet and the source and destination addresses in the header. Thereafter, it despatches the packet through the port GigabitEthernet 0/1 and the gateway IP 141.15.1.2.

Question 3 (a)

The Ethernet frame supports to transmit the maximum of 1500 bytes of the generally. Therefore, it is not possible to encapsulate the 1510 bytes of data in one frame.

It will require two frames to be sent for transmitting the 1510 bytes of data.

Question 3 (b)

The highest capacity of Ethernet frame is 1500 bytes. Therefore, the first frame will contain 1500 bytes of data and the last frame will contain 10 bytes of data. However, the Ethernet frame contains the Ethernet frame header of 14 bytes and those will be also attaches to the frame and sizes of each of the frames will be 1514 and 24 respectively

Part C

Question 1

The organisation currently exists in six different locations. However, it may extend its operations to 10 other locations as well. Therefore, the sub-netting of the IPv6 block 2001:DB8:FAB::/48 is being done for 16 different location.

GIVEN IP BLOCK: 2001:0DB8:0FAB|:0000:0000:0000:0000:0000/48

In IPv6 a given carrying four bits or one nibble will help to create 2⁴ or 16 numbers of Sub networks.

Location 1:

Range Starts 2001:0DB8:0FAB:0|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:0|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 2:

Range Starts 2001:0DB8:0FAB:1|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:1|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 3:

Range Starts 2001:0DB8:0FAB:2|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:2|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 4:

Range Starts 2001:0DB8:0FAB:3|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:3|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 5:

Range Starts 2001:0DB8:0FAB:4|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:4|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 6:

Range Starts 2001:0DB8:0FAB:5|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:5|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 7:

Range Starts 2001:0DB8:0FAB:6|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:6|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 8:

Range Starts 2001:0DB8:0FAB:7|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:7|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 9:

Range Starts 2001:0DB8:0FAB:8|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:8|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 10:

Range Starts 2001:0DB8:0FAB:9|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:9|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 11:

Range Starts 2001:0DB8:0FAB:A|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:A|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 12:

Range Starts 2001:0DB8:0FAB:B|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:B|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 13:

Range Starts 2001:0DB8:0FAB:C|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:C|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 14:

Range Starts 2001:0DB8:0FAB:D|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:D|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 15:

Range Starts 2001:0DB8:0FAB:E|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:E|FFF:FFFF:FFFF:FFFF:FFFF/52

Location 16:

Range Starts 2001:0DB8:0FAB:F|000:0000:0000:0000:0000/52

Range Ends: 2001:0DB8:0FAB:F|FFF:FFFF:FFFF:FFFF:FFFF/52

Now, after providing these IP blocks to the network administrators of these location. They will be able to easily to Subnet these blocks easily to 200 Subnets of equivalent sizes. To create 200 Subnets it will require borrowing 8 bit or two nibbles so it will give 2⁸ or 256 Subnets. However, 7 bits are borrowed then it will allow forming only 2⁷ or 128 Subnets.

Question 2 (a)

To configure the DHCP in the router, connect the router to the workstation using a console cable in order to access the configuration terminal of the router. After getting access to the configuration terminal, enter the following commands to configure the router:

R1# configure terminal

R1(config)# interface gigabitEthernet 0/0

R1(config-if)# ip address 192.168.1.1 255.255.255.0

R1(config-if)# no shutdown

R1(config-if)# exit

R1(config)# ip dhcp pool mypool

R1(dhcp-config)# network 192.168.1.0 255.255.255.0

R1(dhcp-config)# default-router 192.168.1.1

R1(dhcp-config)# exit

R1(config)# ip dhcp excluded-address 192.168.1.1

R1(dhcp-config)# Ctrl+Z

After applying this configuration in the router, move to the server and printer settings and in their configuration options opt for obtain IP addresses automatically. Thereafter all the devices on the network will be provided with an IP address from the IP pool.

Question 2 (b)

R1# configure terminal – This command turns on the configuration mode of the router.

R1(config)# interface gigabitEthernet 0/0 - This command selects the Gigabit Ethernet 0/0 port of router for futher configuration on that Particular interface.

R1(config-if)# ip address 192.168.1.1 255.255.255.0 – This command assigns the ip address 192.168.1.1 and its Subnet mask 255.255.255.0 to the Gigabit Ethernet 0/0 port of the router.

R1(config-if)# no shutdown – This command turns the port Gigabit Ethernet 0/0 on.

R1(config-if)# exit – This command takes back to the previous configuration mode or leaves the Gigabit Ethernet 0/0 interface configuration mode

R1(config)# ip dhcp pool mypool – This command generates a dhcp pool and its name that will contain a range of ip addresses for DHCP purposes.

R1(dhcp-config)# network 192.168.1.0 255.255.255.0 – This command includes all the ip addresses in the 192.168.1.0/24 network id to that IP pool. That is the range 192.168.1.1 to 192.168.1.254

R1(dhcp-config)# default-router 192.168.1.1 – This command assigns the default routers Ip or the default gateway in the DHCP pool.

R1(config)# ip dhcp excluded-address 192.168.1.1 – This command excludes the IP 192.168.1.1 from the pool because it is already assigned to the router.

R1(dhcp-config)# Ctrl+Z - This command saves the configuration.

References

Ando, Y., Nagao, H., Miyao, T. and Shudo, K., 2014, September. Routing table construction method solely based on query flows for structured overlays. In Peer-to-Peer Computing (P2P), 14-th IEEE International Conference on (pp. 1-5). IEEE.

Goralski, W., 2017. The Illustrated network: How TCP/IP works in a modern network. Morgan Kaufmann.

Ko, Y., Box, Inc., 2014. System and method for load balancing multiple file transfer protocol (FTP) servers to service FTP connections for a cloud-based service. U.S. Patent 8,719,445.

Yan, D., 2014. Applications of Packet Tracer simulator in the course< Router Configuration. Electronic Test, 8, 019.