Text file: BOCK_chunk_03.txt
Reading lines: 1-500 (file has 501 lines)
Latest content with line numbers:
1	based on its MAC
2	
3	destination IP
4	
5	destination
6	
7	address table
8	
9	addresses
10	
11	addresses
12	Network
13	
14	Leads to
15	
16	Improves network
17	
18	Enhances overall
19	
20	efficiency
21	
22	inefficient use of
23	
24	performance by
25	
26	network efficiency
27	
28	network
29	
30	reducing
31	
32	and performance
33	
34	bandwidth as all
35	
36	unnecessary traffic by optimizing data
37	
38	devices receive all
39	
40	in other parts of
41	
42	traffic flow
43	
44	traffic
45	
46	the network
47	
48	between network
49	segments
50	
51	security
52	
53	Provides a lower
54	
55	Enhances security
56	
57	Improves security
58	
59	level of security as by isolating traffic
60	
61	by separating
62	
63	all connected
64	
65	within each port,
66	
67	network segments,
68	
69	devices can "see"
70	
71	creating separate
72	
73	preventing direct
74	
75	the same traffic
76	
77	broadcast domains access between
78	
79	different networks
80	Table 3 compare between HUB, Switch, Router
81	
82	Network Topology
83	Types of Network Topology
84	The network arrangement comprising nodes and connecting lines via sender and
85	receiver is referred to as Network Topology. The various network topologies are:
86	Point to Point-to-Point topology
87	
88	31 | P a g e
89	
90	Point-to-point topology is a type of topology that
91	works on the functionality of the sender and
92	receiver. It is the simplest communication between
93	two nodes, in which one is the sender
94	
95	Figure 11 Point-to-point topology
96	
97	and the other one is the receiver. Point-to-Point provides high bandwidth.
98	
99	Mesh Topology
100	In a mesh topology, every device is connected to another device
101	via a particular channel. In Mesh Topology, the protocols used are
102	AHCP (Ad Hoc Configuration Protocols), DHCP (Dynamic Host
103	Configuration Protocol), etc.
104	In Figure: Every device is connected to another via dedicated channels.
105	These channels are known as links.
106	
107	Figure 12 mesh topology
108	
109	Suppose, the N number of devices are connected with each other in a mesh topology,
110	the total number of ports that are required by each device is N-1. In Figure , there
111	are 5 devices connected to each other, hence the total number of ports required by
112	each device is 4. The total number of ports required = N * (N-1).
113	Suppose, N number of devices are connected with each other in a mesh topology,
114	then the total number of dedicated links required to connect them is NC2 i.e. N(N1)/2. In Figure, there are 5 devices connected to each other, hence the total number
115	of links required is 5*4/2 = 10.
116	Star Topology
117	In Star Topology, all the devices are connected to a single hub through a cable. This
118	hub is the central node and all other nodes are connected to the central node.
119	32 | P a g e
120	
121	The hub can be passive , not an intelligent hub
122	such as broadcasting devices, at the same time
123	the hub can be intelligent known as an active
124	hub. Active hubs have repeaters in them.
125	Coaxial cables or RJ-45 cables are used to
126	connect the computers. In Star Topology, many
127	popular Ethernet LAN protocols are used as
128	CD(Collision
129	
130	Detection),
131	
132	CSMA
133	
134	(Carrier
135	
136	Figure 13 Star Topology
137	
138	Sense Multiple Access), etc.
139	Bus Topology
140	Bus Topology is a network type in which every computer and network device is
141	connected to a single cable. It is bi-directional. It is a multi-point connection and a
142	non-robust topology because if the backbone fails the topology crashes. In Bus
143	Topology, various MAC (Media Access Control) protocols are followed by LAN
144	ethernet connections like TDMA, Pure Aloha, CDMA, Slotted Aloha, etc.
145	Ring Topology
146	A Ring Topology, it forms a ring connecting
147	devices
148	
149	with
150	
151	exactly
152	
153	two
154	
155	neighboring
156	
157	devices. Several repeaters are used for Ring
158	topology with a large number of nodes,
159	because if someone wants to send some data
160	to the last node in the ring topology with 100
161	nodes, then the data will have to pass through
162	99 nodes to reach the 100th node.
163	Hence to prevent data loss repeaters are used
164	in the network.
165	33 | P a g e
166	
167	Figure 14 Ring Topology
168	
169	The data flows in one direction, i.e. it is unidirectional, but it can be made
170	bidirectional by having 2 connections between each Network Node, it is called
171	Dual Ring Topology. In-Ring Topology, the Token Ring Passing protocol is used
172	by the workstations to transmit the data.
173	Tree Topology
174	This topology is the variation of the Star topology. This topology has a hierarchical
175	flow of data. In Tree Topology, protocols like DHCP and SAC (Standard Automatic
176	Configuration ) are used.
177	
178	Figure 15 tree Topology
179	
180	34 | P a g e
181	
182	IN Figure: the various secondary hubs are connected to the central hub which
183	contains the repeater. This data flow from top to bottom i.e. from the central hub to
184	the secondary and then to the devices or from bottom to top i.e. devices to the
185	secondary hub and then to the central hub. It is a multi-point connection and a nonrobust topology because if the backbone fails the topology crashes.
186	Hybrid Topology
187	This topological technology is the combination of all
188	the various types of topologies we have studied above.
189	Hybrid Topology is used when the nodes are free to
190	take any form. It means these can be individuals such
191	as Ring or Star topology or can be a combination of
192	various types of topologies seen above. Each individual
193	topology uses the protocol that has been discussed
194	earlier.
195	
196	35 | P a g e
197	
198	Figure 16 Hybrid Topology
199	
200	➢ Servers
201	Servers are strong computers that store, manage, and distribute data within a
202	network. They are hardware components of networks. Compared to standard
203	personal computers, they have much more processing power, memory, and storage
204	capacity.
205	Because they frequently hold sensitive data and offer essential services that must
206	always be available, they are made to be incredibly dependable and safe.
207	Specialized operating systems for large user counts are frequently run on servers.
208	A hardware server's main job is to receive and process requests from networked
209	computers, sometimes referred to as clients. These requests may pertain to email
210	distribution, file retrieval and transmission, or website serving.
211	
212	There are many types of servers:
213	File server: A server dedicated to storing and managing files for all users in the
214	network.
215	Web server: Hosts websites and makes them available over the internet. Database
216	server: Provides database services and responds to queries from clients. Game
217	server: A server used for online gaming which hosts multiplayer matches. DNS
218	server: Translates domain names into IP addresses.
219	Mail server: Manages, stores, and transfers emails over the network.
220	
221	36 | P a g e
222	
223	Every server has the option of being shared (doing several jobs) or dedicated
224	(handling only one kind of server task). Server rooms, also referred to as data
225	centers, are designated areas where servers are kept in vast networks.
226	
227	➢ Clients
228	Computers or other networked devices that make use of the resources and services
229	offered by servers are known as clients. They are a type of network hardware
230	component. The client program is the software that each client uses to communicate
231	with the server.
232	The devices known as clients start communication sessions by submitting requests
233	to servers, which reply to the clients, in a standard client-server architecture. These
234	requests could be for services, like printing a paper, or data, like getting a web page
235	back.
236	Client devices can include hardware such as printers and scanners in addition to
237	personal computers (desktops and laptops), cellphones, and tablets. Depending on
238	their processing capability and the proportion of the application and its data that is
239	stored locally versus on the server, clients can also be classified as thick or thin
240	clients.
241	In conclusion, clients are network endpoints that communicate with servers to gain
242	access to common services and resources.
243	
244	➢ Peers
245	When discussing networking, a computer or other device that is a part of a peer-topeer (P2P) network is referred to as a "peer." In peer-to-peer networking, every
246	peer—also referred to as a node or member—is treated equally and has the ability
247	to communicate with other peers on the network by acting as a client or server.
248	37 | P a g e
249	
250	Often serving as both clients and servers, peer devices allow the direct sharing of
251	resources amongst one another, eliminating the need for a middleman server.
252	Examples of these resources include content, disk storage, and CPU power.
253	Blockchain networks and file-sharing networks are two well-known examples of
254	this.
255	Peers can simply be any regular computer or device that has the appropriate peerto-peer networking software installed on it as a hardware component. The device's
256	ability to function as a peer is provided by its software, but it may also include
257	standard hardware parts like a CPU, memory, storage, and a network interface for
258	network connectivity.
259	
260	38 | P a g e
261	
262	Chapter 3
263	Introduction to Firewalls
264	Firewalls are essential components of network security, acting as the first line of defense
265	against unauthorized access and malicious traffic. Let's delve into their definition,
266	purpose, and historical development.
267	Definition and Purpose
268	A firewall is a network security device that monitors incoming and outgoing traffic
269	flowing between a private network (like your home network) and an external network
270	(typically the internet).
271	Here's a breakdown of a firewall's key purpose:
272	•
273	•
274	
275	•
276	
277	Traffic Inspection: Firewalls meticulously examine incoming data packets,
278	checking their origin, destination, type (email, web browsing, etc.), and content.
279	Rule-based Decisions: Predefined security policies determine how the firewall
280	treats each packet. It might allow legitimate traffic, block suspicious activity, or
281	log information for further analysis.
282	Access Control: By filtering traffic, firewalls restrict unauthorized access
283	attempts to your network resources, preventing hackers and malware from
284	infiltrating your system.
285	
286	In simpler terms, imagine your home with a security guard at the entrance. The guard
287	checks everyone entering (incoming traffic) and verifies their identity and purpose. Only
288	authorized visitors with legitimate reasons are allowed in, while others are turned away
289	(blocked traffic).
290	Historical Background
291	The concept of a firewall has evolved over time, keeping pace with the growing
292	complexity of network threats. Here's a glimpse into the historical journey of firewalls:
293	•
294	•
295	
296	Early Packet Filters (1970s-1980s): These basic firewalls simply filtered traffic
297	(Content truncated due to size limit. Use page ranges or line ranges to read remaining content)