1. Give the difference between a MAC and an IP address
MAC – (Media
Access Control) – It is the machine address and it will never change. It is the
unique machine address given to your device. Cannot be changed.
EX:
IP – (Internet
Protocol) – It is designed to allow one computer or another digital device to
communicate with one another via the Internet. It is a set of rules that govern
Internet activity and facilitate completion of a variety of actions on the World
Wide Web. Can be changed but still unique
EX: Version 4 - 192.168.11.10
2. Explain each section of the IP Address Header.
(A) Version
|
(B) Header Length
|
(C) Service Type
|
(D) Total Length
|
(E) Identification
|
(F) Flags
|
(G) Fragment Offset
|
(H) TTL
|
(I) Protocol
|
(J) Header Checksum
|
(K) Source IP Address
|
(L) Destination IP Address
|
(M) Options
|
(N) Padding
|
(A)
PROTOCOL VERSION (4bits)–
It signifies the current IP protocol version being used.
(B)
HEADER LENGTH (4bits)–
It provides the length of the IP header. It also includes IP options. It is 4
bits so the maximum header length allowed is 60 bytes.
(C)
TYPE OF SERVICE (8bits)–
The first three bits of this field are known as precedence bits and are ignored
as of today. The next 4 bits represent type of service and the last bit left
unused.
(D)
TOTAL LENGTH (16bits) – It represents the total IP datagram
length in bytes. Since the header length gives the length of the header and
this field gives total length so the length of data and its starting point can
easily be calculated using this two fields.
(E)
IDENTIFICATION (16bits) –
Is it used for uniquely identifying the IP datagrams. This value is incremented
every-time and IP datagram is sent from source to destination. This field comes
in handy while reassembly of fragmented IP datagrams.
(F)
FLAGS (3bits) –
The first bit is kept reserved for now. The second bit represents “Don’t Fragment
bit”. When this bit is set then IP datagram is never fragmented, rather it is
thrown away if a requirement for fragment arises. The third bit represents the “More
Fragment bit”. If this bit is set then it represents a fragmented IP datagram
that has more fragments after it.
(G)
FRAGMENT
OFFSET (13bits) – In case of fragmented datagram,
this field contains the offset from the start of IP datagram. It is used in
reassembly of fragmented IP datagrams.
(H)
TIME TO
LIVE (8bits) –
Represents number of hop that the IP datagram will go through before being
discarded. When this field becomes zero, the datagram is discarded. So, we see
that this field literally means the effective lifetime for a datagram or
network.
(I)
PROTOCOL (8bits) – Represents the
transport layer protocol that handed over data to IP layer.
(J)
HEADER
CHECKSUM (8bits) –
Represents a value that is calculated using an algorithm covering all the
fields in header. The value ic calculated and stored in header when IP datagram
is sent from source to destination and at the destination side this checksum is
again calculated and verified against the checksum present in header.
(K)SOURCE (32bits) – These fields store
the source address. Since the size of these fields is 32 bits each so an IP
address’s maximum length of 32 bits can be used.
(L)
DESTINATION
IP (32bits) –
This field stores the destination address.
(M)
OPTIONS (Variable
Length) – This field represents a list of options that are active for a
particular IP datagram. This is an optional field that could be or could not be
present.
(N) DATA – this field contains the
data from protocol layer that has handed over the data to IP layer. This field
contains the header and data of the transport layer protocols.
3. List the different IP Address classes with its corresponding
details.
CLASS
|
RANGE OF 1ST OCTET
|
PURPOSE
|
RANGE
|
A
|
1-126*
|
For internetwork
communication
|
0.0.0.0
to 127.255.255.255
|
B
|
128-191
|
128.0.0.0 to
191.255.255.255
|
C
|
192-223
|
192.0.0.0 to 223.255.255.255
|
D
|
224-239
|
Reserved for
multicasting
|
224.0.0.0 to
239.255.255.255
|
E
|
240-254
|
Reserved for search
experiments
|
240.0.0.0 to
255.255.255.255
|
*127 is reserved
4. Identify the IP version 4 public addresses and IP version 4 private
addresses
PUBLIC ADDRESS – an IP address that can be accessed over the
internet. A Public IP address is the globally unique IP address assigned to a
computing device.
STARTS with 10,17,192,127 (EX:192.169.0.0)
PRIVATE ADDRESS – is used
to assign computers within your private space without letting them directly
expose to the internet.
5. Identify the difference between IP version 4 and IP version 6
address.
IPv4 – It is
the underlying technology that makes it possible for us to connect our devices
to the web.
IPv6- The sixth revision to the internet protocol and
the successor to IPv4. It functions similarly to the IPv4 but it does sport one
major difference which it utilizes 128-bit addresses.
6 6. Give the differences between TCP and UDP.
|
TCP
Transmission Control Protocol
|
UDP
User Datagram Protocol
|
RELIABLITY
|
Connection-oriented protocol. When a file or message
send, it will get delivered unless connections fails. If so, the server will
request the lost part. There is no corruption while transferring message.
|
Connectionless protocol. When you send a data or
message, you don’t know if it will get there as it could get lost on the way.
There may be corruption while transferring a message.
|
ORDERED
|
If you send two messages along a connection, one
after the other, you know the first message will get there first, You don’t have
to worry about data arriving in the wrong order.
|
If you send two messages, you don’t know what order
they will arrive.
|
HEAVYWEIGHT
|
When the low level parts of the TCP “stream” arrive
in the wrong order, resend requests have to be sent and all the out of
sequence parts have to be put back together so it requires a bit of work to
piece it together.
|
No ordering messages, tracking connections, etc. It
is just send and forger. This means it is a lot quicker and the network card
have to do very little work to translate the data back from the packets.
|
STREAMING
|
Data is read as a “stream” with nothing
distinguishing where one packet ends and another begins. There may be
multiple packets per read call.
|
Packets are sent individually and are guaranteed to
be whole if they arrive. One packet per one read call.
|
EXAMPLES
|
·
World Wide Web (Apache TCP port 80)
·
E-Mail (SMTP TCP port 25 Postfix MTA)
·
File Transfer Protocol (FTP port 21)
·
Secure Shell (OpenSSH port 22)
|
·
Domain Name System (DNS UDP port 53)
·
IPTV
·
Voice over IP (VoIP)
·
Trivial File Transfer Protocol
·
Online Multiplayer Games
|
7. Explain what is a subnet and subnet addressing.
SUBNET – a logical
grouping of connected network devices. Nodes on a subnet tend to be located in
close physical proximity to each other on a LAN.
SUBNET
ADDRESSING - allows us to split one IP network address into smaller multiple physical networks known as subnetworks.
8. Explain VLSM and identify its purpose.
VLSM – (Variable
Length Subnet Mask) It is a numerical masking sequence or IP address subset,
based on overall network requirements. It allows a network administrator to use
long masks for networks with few hosts and short masks for network with
multiple hosts.
· PURPOSE – It allows you to create
multiple subnets of varying size
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