INTRODUCTION TO CCNA tutorial

INTRODUCTION TO CCNA

The CCNA (Cisco Certified Network Associate) certification title has become the leading entry level certification in computer networking field available today. The CCNA (Cisco Certified Network Associate) certification was developed by Cisco to test a candidate's knowledge of networking at entry level. The CCNA (Cisco Certified Network Associate) certification analyzes the candidate's ability to install, configure, operate, and troubleshoot medium-size routed and switched networks.

The CCNA (Cisco Certified Network Associate) certification is recognized by IT employers when considering a fresher's profile for a vacancy or for a salary hike/promotion for experienced employees. The CCNA (Cisco Certified Network Associate) exam covers a broad range of networking concepts to prepare candidates for the technologies they are likely to work with in today’s network environments.

New version of CCNA examinations (Exam Number 200-301 CCNA Routing and Switching) is available from February 24, 2020.

New CCNA exam – 200-301

Cisco certification program has been drastically changed from Feb. 24, 2020. There are no longer multiple different CCNA exams and certifications – only a single, comprehensive exam is available. The new exam’s code is 200-301 CCNA and its full name is Implementing and Administering Cisco Networking Technologies. According to Cisco, the new exam “covers a broad range of fundamentals based on the latest technologies, software development skills, and job roles“.

Under the old CCNA certification program, there were multiple concentration exams for different learning paths. However, under the new rules, the following certifications have all been replaced by the new CCNA:

• CCNA Cloud
• CCNA Collaboration
• CCNA Data Center
• CCNA Industrial
• CCNA Routing and Switching
• CCNA Security
• CCNA Service Provider
• CCNA Wireless
• CCDA (Cisco Certified Design Associate)

So, the specialization at the CCNA level is going away – you now choose your specialization at the CCNP level.

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COMMUNICATION USING A NETWORK tutorial

   COMMUNICATION USING A NETWORK

Data communication:- Transmission of information between two computers or nodes.

                     Basic Computers

1.Sender  2.Receiver 3.Medium  4.Message 5.Protocol

SIGNALING TECHNIQUES - 1

• Two tyes of signaling techniques,

1. BASEBAND
2. BROADBAND

                 BASEBAND SIGNALS

Uses signale frequency to transmit data.

• Transmit information in digital form.

SIGNALING TECHNIQUE - 2

                 BROADBAND SIGNALS

• Data is transmitted using more than one frequency.
• Uses analog signal.
• Adds additional information to carrier signals by proces of modulation.

Network interface card (NIC)

• Hardware device used to connct different computers on network.
• Serves as a link for sending and receiving data on a netok.
• MAC address is address assigned by IEEE to identify network card.

                            Types of NIC

       There are two types of NIC.

1. Ethernet card
2. Token ring card

            ETHRENET CARD

• Used in devices which are conncted using ETHERNET technology.
• Two types of ETHERNET network card - wired nd wireless.
• The choice depends on type of network card.

Types of ETHERNET CARD - 1

1. 10Base-5 (thicknet) NIC
2. 10Base-2

Types of ETHERNET CARD - 2

1. 10BaseT
2. Fiber - optic

          TOKEN RING CARD

• Used to connect to a TOKEN RING network.
• Assigned a MAC address by IEEE.
• Maximum of two TOKEN RING CARD can be installed at any node.
• Consists of 9 pin DIN type connector which onnects card to network cable.

Light on NIC and HUB

• Different LEDs on NIC

1. Link LED
2. ACT LED
3. Speed LED
4. Collision LED

• LED on HUB

1. Power LED
2. Port LED

                MAC address

• Also known as hardware or physical address.
• Used to identify nodes at lower levels of the OSI model.
• ID assigned by IEEE.
• Hardware address hard-coded into NIC.
• Nodes on network identified by MAC address.
• Is a 12-digits hexadecimal number (48-bits address).

                    MAC vs IP address

MAC address                           IP address

1.Function at data link layer.1.Function at network late.

2.It is a physical address.     2.It is logical address.

3.It is fixed.                   3.It changes with the relocation

                                          of device from one network to

                                               another.

4.It is a 48-bits address.      4.It is a 32-bits address.

Tone generators and Probe - 1

• Tone generator is a network troubleshooting tool.
• Consists of signale or multi-Tone signale, to test leads and a 4-conductor modular cable.
• Acts like radio transmitter.
• PROBE:-

1. Works like a radio receiver.
2. Catches a tone when placed near wire.

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IP address ( IP v4 & v6 ) tutorial

                           IP address

Introduction:-

• An internet protocol address (IP address) is a numerical lable assigned to each device (e.g. computer,printer) participating in a computer network that uses the internet protocol for communication.
• An IP address is binary number that uniquely identities computers and other devices on a TCP/IP network.
• You can probably work with decimal numbers much easier than with the binary numbers needed by the computer.
• Working with binary numbers is time-consuming and error-prone.

                          Objects

• The 32-bit IP address is broken up into 4 octets, which are arranged into a dotted-deciml notation scheme.
• An octet is a set of 8-bits and not a musical instruments
• EXP of an IP v4

                             172.64.126.52

              THINKING IN BINARY

• The binary system uses only 2 values 0 & 1 to represent numbers in position.
• Representing increasing powers of 2.
• We all are accustomed to thinking and working in the decimal system, which is based on the number 10.

           THINKING IN BINARY (cont.)

• To most humans , the number 124 represents 100+20+4.
• To the computer this number is 1111100, which is 64(26)+32(25)+16(24)+8(23)+4(22)+0+0.

             IP address classes

• IP addresses are decided into 5 classes each of which is designed with the alfabetic letters A to E.
• Class D addresses are used for multicasting.
• Class E addresses are reserved for testing some mysterious future use.

         IP ADDRESS CLASSES (cont.)

• The 5 IP address classes are split up based on the value in the 1st octet.

IP address class assignment

Classes                           frist octet value

Class A                                      0 - 127

Class B                                      128 -191

Class C                                      192 - 223

Class D                                      224 - 239

Class E                                      240 - 255

• Using the ranges, you can determine the class of an address from its 1st octet value.
• An address beginning with 120 is a class A address, 155 is a class B address and 220 is a class C address.

ARE YOU THE HOST OR THE NETWORK:-

• The 32-bits of the IP address are devided into network and host portions, with the octets assigned as a part of one or the other.

NETWORK AND HOST PRESENTATION BY IP ADDRESS CLASS:-

Class             octet 1 octet 2        octet 3 octet 4

Class A        network   host host             host

Class B        network   network host             host

Class C       network   network network       host

• Each network is assigned a network address and every device or interface (such as a router port) on the network is assigned a host address.
• There are only 2 specific rules that govern the value of the address.

TYPES OF IP ADDRESS

     there  are 2 types of IP address…..

1. IPv4
2. IPv6

Different between IP v4 and IP v6

                         IP v4                             IP v6

Deployed             1981             1999

Address size       32-bit number   128-bit number

Address formal  dotted decimal         hexadecimal

                                 notation                 notation

                          192.149.252.76    3FFE:F200:0234:AB00:

                                                    0124:4567:890:ABCD

Prefix notation  192.149.0.0/124 3FFE:F200:0234::/48

Number of    232=~4,294,967,296  2128=~340,282,366,920,

Address                                         938,463,374,607,431,

                                                       768,211,456

IP ADDRESS CLASSIFICATION:-

IP addresses are devided into 5 classes…..

Class           Add. Range                 supports

Class A      1.0.0.1 to           supports 16 million hosts 

                 126.255.255.254       on each of 127 network.

Class B      128.1.0.1 to           supports 65000 hosts on 

                  191.255.255.254      each of 16000 network.

Class C      192.0.1.1 to         supports 254 hosts on

                   223.255.254.254    each of 2 million network.

Class D      254.0.0.0 to         Reserved for multicast 

                  239.255.255.255       groups

Class E      240.0.0.0 to         Reserved for future use or 

                  254.255.255.254   research and development

                                                       perposes.

                      SUBNET MASK

A subnet mask is used to devide IP address into two parts. One part identities the host(computer) the other parts identities the network to which it belongs.

Class A                 network host     host host

Subnet mask         255 0            0 0

Class B                network network     host host

Subnet mask          255 255           0 0

Class C               network network   network host

Subnet mask        255 255           255 0

DIFFERENCE BETWEEN STATIC & DYNAMIC IP

             static IP                           dynamic IP

1.A permanent numeric address 1.A temporary IPadd.

        assigned to the host in       assigned to the host in

           a network.                                a network.

2.Assigned manually by the    2.Assigned by the DHCP

    network administrator.            server automatically.

3.Does not changes                         3.Changes 

    automatically                              automatically

     after it's assigned to             if connection is reset 

     the computer.                         or DHCP lease expires.

4. Less secure.                  4. More secure as compared

                                                   to static IP.

5.Used for dedicated servers    5. Used for connecting

 like FTP, Mail server                lagre network to the 

         and VPN.                   internet and communication.

DIFFERENT BETWEEN PUBLIC AND PRIVATE IP

     private IP                               public IP

1.Used with LAN or network  1.Used on public network

not recognized over internet. recognized over internet.

2.Assigned by LAN        2.Assigned by service provider

      administrator                        IANA.

3.Unique only in LAN3.Unique globally cost associated

 free of change.                  with using public IP.

      RANGE OF PUBLIC AND PRIVATE IP

  Class                private IP         public IP

Class A               10.0.0.0 to         1.0.0.0 to

                       10.255.255.255             9.255.255.255

                                                11.0.0.0 to 126.255.255.255

Class B              172.16.0.0 to         128.0.0.0 to

                      172.31.255.255             172.15.255.255

                                           172.32.0.0 to 191.255.255.255

Class C            192.168.0.0 to           192.00.00 to

                      192.168.255.255           192.167.255.255

                                        192.169.0.0 to 223.255.255.255

           SPECIAL IP ADDRESSES

IP addresses which are never used on the public internet..

• Network address

All hosts = 0; e.g. 158.108.0.0/16

• Directed broadcast address

All hosts = 1; e.g. 158.108.255.255/16

• Limited broadcast address Broadcast to local network

All hosts = 1; e.g. 255.255.255.255

• This computer address

All hosts = 0; e.g. 0.0.0.0

• Loopback address

127.0.0.0/8 ➡️ 127.X.X.X

        APIPA = Automatic private IP address.

                 ADDRESS STRUCTURE

An IP v6 address is made of 128- bits devided into eight 16-bits blocks. Each block is then converted in to 4 - digit Hexadecimal numbers separated by colon symbols.

          For example, given below is a 128-bits IP v6 address represented in binary formate and devided in to eight 16-bits blocks.

        2001:0000:3238:DFE1:0063:0000:FEFB

Even after converting into Hexadecimal formal, IP v6 address remains long IP v6 provides some rules to shorten the address. The rules are as follow……..

Rule 1:- Discard leading zeroes in block 5 0063, the leading two as can be omitted , such as  (5th block).

        2001:0000:3238:DFE1:63:0000:0000:FEFB

Rule 2:- If two or more blocks contain consecutive zeroes, omitt them all and replace with double colon sign (::) such as (6th and 7th block).

        2001:0000:3238:DFE1:63::FEFB

Rule 3:- Consecutive blocks of zeroes can be replaced only once by :: so if there are still blocks of zeroes in the address , they can be shrunk down to a single zero, such as (2nd block).

       2001:0:3238:DFE1:63::FEFB

IP v6 address                      meaning

:: / 128                              unspecified address

:: / 0                                  default route

:: 1 / 128                           loopback address

• As shown in the table, the address 0:0:0:0:0:0;0:0:/128 does not specify anything and is said to be an unspecified address . After simplifying, all the OS are compacted to :: / 128.

• In IP v4 the address 0.0.0.0 with netmask 0.0.0.0 representes the default route. The same concept is also applied to IP v6 address 0:0:0:0:0:0:0:0 with netmask all as represents the default route after applying IP v6 rule this address is compressed to ::/0.

• Loopback address in IP v4 represente by 127.0.0.1 to 127.255.255.255 serviesed but in IP v6 only 0:0:0:0:0:0:01/128 represents the loopback address after loopback address it can be represented as ::/128.

Types of IP v6 address

1. Global unicast address:- These address are routable on the internet and start with 2001 as the prefix group global unicast address are the equivalent of IP v4 public addresses.

|Global routing prefix|     subnet mask| interface ID|

       8-bits                                16-bits 64-bits

2. Link local address:- This is one of the two internet address types that are not routed on the internet link local addresses are used inside an internet network are self assigned and start with FE80; as the prefix ground the frist 16-bits of link local address is always set to 1111 1110 1000 0000 (FE80) the next 48-bits are set to 0.

| 1111 1110 1000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 | interface ID|

3. Unique local address:- This type of IP v6 address is globally unique, but it should be used in local communication. The second half of this address contain interface ID and the frist half is devided among prefix, local bits,global ID and subnet ID.

  PREFIX       |L| global ID |   subnet ID | interface ID|

1111 1110     1-bit 40-bits         16-bits 64-bits

Scope of IP v6 unicast addresses

The scope of link local address is limited to the segment. Unique local address are locally global, but are not routed over the internet, limiting their scope to an organization's boundary. Global unicast addresses are globally unique and recognizable. They shall make the essence of internet. 

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