COIT20261 Network Routing And Switching

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13-07-2021

Question:

You are the Network Administrator for a startup company that has been granted a new block of addresses starting with the address 139.145.56.0/22.

Calculate the total number of addresses available in this block including all the special addresses. Show your calculation
As Network Administrator, you need to distribute the available addresses on a departmental needs basis (meaning not allocating more than you have to), with 4 new subnets determined as follows:

Create the 4 subnets. For each subnet, list the subnet or first address, the last address, and the subnet mask in CIDR format. Show your calculations for all subnets, briefly showing how you arrived at the sub-block addresses.

How many addresses are left unallocated? Show your calculation.

An IP datagram 5,600 bytes long (including header with no options) arrives at a router, which determines that the next destination has an MTU of 1,500 bytes. Answer the following questions, showing your calculations and reasoning.

Assuming that the router decides to fragment the packet into 4 fragments, for each fragment, determine a correct size, and identify the starting byte and ending byte
Calculate the fragmentation offset for each fragment
The total number of bytes from all 4 fragments leaving the router should be greater than the initial datagram size that arrived. Explain why this is so

Hints: Working out part (a) can be a fiddly (messy) exercise and you may find it helpful to use a spreadsheet to work out appropriate sizes and offsets. Remember that the offset needs to be evenly divisible by 8, as explained in the textbook. You may need to do additional reading to understand the process if it is unclear to you – Forouzan is a good place to start.

Research and review appropriate materials, including the textbook, and answer the first two questions (a & b).

Define the terms and discuss the relationship between Autonomous Systems, Inter-domain routing, and Intra-domain routing

Identify the major routing protocols associated with Inter-domain and Intra-domain routing and list their similarities and differences Finish by commenting on why we need different protocols for Inter-domain and Intra-domain routing

Study the two articles listed below – both are freely available on the Internet. You may use other references in addition to these, as needed. Then answer the remaining 3 questions (c, d & e).

Briefly summarize in your own words the problems with current routing methods that the authors have identified.
Contrast and compare the concepts of embedded routing and extensible routing.
How does the proposal of Routing As A Service (RAAS or just RAS) address the problems with current routing methods.

Answer:

Routing table of router R2:

Routing table of router R3:

Given IP Block is 139.145.56.0/22

Subnet Mask is 255.255.252.0 (It is a classless SNM)

If we take the SNM and convert the decimal numbers to binary

111111111 11111111 11111100 00000000,

The host's formula is 2^{n – 2} [ - 2 = 2 IPs are network and broadcast

address ]

= 2¹⁰

= 1024

126.145.56.0 - 126.145.59.255

Total number of addresses including network and broadcast address (NETworking, 2013):

1024

Department	Subnet address	Last address	Mask
Marketing	139.145.56.0/25 The host's formula is 2 n - 2 Subnet : 27-2 256-128 = 128 Hosts =2 x 2 x 2 x 2 x 2 x 2 x 2 = 128 Subnet : 255.55.255.128 usable rage is :139.145.56.129 – 139.145.56.254 the Subnet address is : 139.145.56.128/25	139.145.56.127	255.255.255.128
Accounting	139.145.56.128/25 The host's formula is 2 n - 2 27 =2 x 2 x 2 x 2 x 2 x 2 x 2 = 128 255-128 = 128 Subnet : 255.55.255.128 usable rage is :139.145.56.129 – 139.145.56.254 the Subnet address is : 139.145.56.128/25	139.145.56.255	255.255.255.128
Head Office	139.145.57.0/26 The host's formula is 2 n - 2 Subnet : 27-2 /26 =2 x 2 x 2 x 2 x 2 x 2 = 64 256-64 = 192 Subnet : 255.55.255.192 Usable rage is :139.145.57.1 – 139.145.57.62 The subnet is:139.145.57.0/26	139.145.57.63	255.255.255.192
Cust Services	139.145.57.64/28 24 =2 x 2 x 2 x 2 = 16 256- 16 = 240 Subnet : 255.55.255.240 usable rage is :139.145.57.65 – 139.145.57.78 the Answer is :139.145.57.64/28	139.145.57.79	255.255.255.240

Total number of address in this subnet is 1024 since is a /22 subnet.

11111111.11111111.11111100.00000000.

Used IP Subnet

The starting from 139.145.56.0 to 139.245.57.79.

IP range in the full subnet is 139.145.56.0 to 139.145.59.255

Free IP range in this subnet: 139.145.57.80 – 139.145.59.255.

IP address in 139.145.58.0 – 255 IP addresses

Used IP’s : 80, Free IP’s : 175 IP addresses

IP address in 139.145.59.0 – 255, Free IP addresses: 255

Total no of Free IP addresses : 430

In the task IP datagram size is 5,600 bytes including header.

The router receive the packet size of 5,600 bytes.

The datagram fragmented as below.

Fragmentation	Offset	Length
Fragment-1	0	1500
Fragment-2	185	1480
Fragment-3	370	1500
Fragment-4	612	700
Fragment-5	5120	5600

The reason is,

The Four fragments are additional creates the IP headers and increasing the length up to 60 bytes. (Lifewire, 2017).

Collection of IP networks and routers is called as autonomous system. It do not use the independent variable.
The inter domain routing is used to describes the all router information and it determines the number of domain traversed in the network. The inter domain routing is connect the two service providers and it has own autonomous system.

The intra domain focus on the distributing the routes in the user network. It depends on link quality and load balancing. It specify the subnet routes.

The Top routing protocols are listed below.

RIP(Routing Information protocol)

This protocol is used to enabling the routers. It does not supports the IPv6 network. IT supports only the IPv4. It utilizes the user datagram protocol ports 521 and 520.

OSPF(Open Shortest path protocol)

It involves the network traffic schedule, restriction of hip count and internal networks.

IGRP(Internet gateway routing protocol)

This protocol use the classless internet protocols. It mainly used to increase the routing algorithms but it does not supports the routing hierarchies. It provide the easier configuration and better performance.

IS-IS(Intermediate system to intermediate system)

This protocol is similar to the Open shortest path protocol. It use the networking address. It does not supports the internet protocol network.

Why inter-domain/intra-domain protocols

The Inter domain network use the BGP routing protocol. Because it use the internet service provider.
So the large enterprise networks are use the BGP routing protocols.
The BGP Deployment is used to provide the high quality of services within the networks.
The intra domain network is use the shortest path routing protocol. Because it depends the link matrices and it gives stability and efficiency network. The Shortest path routing protocols are listed below.
EIGRP
OSPF

The

he Routing method has the two main problems such as,

Routing loops
Black hole.

The Routing methods are listed below.

Static routing
Dynamic routing
Default routers
Directly connected interface

The Routing loops is the main problem for the routing method. IT contains the all router information. If the router information are wrong, here occur the routing method problems. It use the IPX packets, IPX hosts and hop count.

Another problem is black hole because it use the datagram and connectionless protocols. It does not gives the successful packets.

Embedded Routing

Embedded routing provides the Gateway with multitude LAN by using the wireless and wired links.
The Configuration of Embedded routing use the DHCP server.
The DHCP server is mainly used to assign the Internet protocol address.
The embedded routing use the network address translator and it used to translate the public IP addresses and Local addresses.

Extensible routing

The next generation of routing platform is extensible routing.
Extensible routing is used to increase the large enterprise networks.
It delivers the scalability, versatility of the network and provides the high efficiency of the network.

It determine the cloud service demands.

The RAAS means Renin-Angiotensin-aldosterone system. This system is used to allow the customized routing.
The RAAS have the challenge between the network administrators and it describes the autonomous system, routing management and end to end path.
RAAS system has the routing control and it requires to solving the routing problem.
The RAAS third party elements are involving the routing services. It use the routing methods.
The Routing methods is used to increase the flexibility of the network.

The RAAS support the higher level control interface.

The limit of hop is depends on the IPv6 packet traversed links. The IP address source and destination length is 128 bits. The Upper layer PDU and extension headers are depends on payload length field.

References

Lifewire. (2017). Top 5 network routing protocols demystified. [online] Available at: https://www.lifewire.com/top-network-routing-protocols-explained-817965 [Accessed 18 May 2017].

NETworking. (2013). 1st ed. [Hong Kong]: Regional NET Coordinating Team, NET Section, CDI, EDB.