CCNA Study Notes

Routers:

In 1992 main products of Cisco were Gateway Servers i.e.

AGS – Advanced Gateway Server

MGS – Mid-Range Gateway Server

IGS – Integrated Gateway Server

CGS – Compact Gateway Server

AGS+ – Advanced Gateway Server Plus

Routers are of two types, Modular and Non-Modular

1.Modular

Routers will not have fix interfaces, can be added or removed whenever required.

2.Non-Modular

Routers will have fix interfaces, cannot be added or removed, they are fixed.

SERIES MODELS

Each series will have different models Each models will have different features or functions

700 701,702,703,704,710 (supports ISDN Technology)

800 801,803,805,810 (supports ISDN+Leased line connection)

1000 1001,1003,1010,1011,1015

1100 1101,1102,1102,1115

1400 1401 – 1411

1600

1700

2500

2600

3600

4000

5000

7000

12000GSR

Gigabit Switched Routers

Products of Cisco:

Router

Switches

Bridges

Brouters

Repeaters

PIX – Packet Information Exchange

VPN Concentrator

AAA Server – Authentication, Authorizing, Accounting Server

IDS – Intrusion Detection System

Policy Manager

Fibre Optics

CRS – Carrier Routing System (provides 9.6TeraBytes per second)

CMTS or UBR – Cable Modem Terminating System

Network

Connection of two or more nodes over the physical media is called as Network.

Networking

Connection of two or more nodes over the physical media and sharing the resources is called as Networking.

Types of Network:

1.Peer-to-Peer Network

Peer meaning client, Operating system used as client are win95, 98,NT4.0 Workstation, Win2000 prof, ME, XP prof.

Workgroup is a small group of computers where no centralized administration and no security is provided.

2.Server based Networks

Server is the one that serves the resources to clients.

Client is the one that requests for the resources from server.

Non-dedicated Server is the system that works both as client and server.

Operating system used as server is WinNT 3.51, 4.0, Win2000server, Win2003server.

Domain

Logical group of computers where centralized administration and security is concerned.

Further types of network:

PAN – Personalized Area Network

LAN – Local Area Network

CAN – Campus Area Network or BAN – Branch Area Network (within 2km diameter using FDDI)

SAN – Storage Area Network

MAN – Metropolitan Area Network (takes support of PSTN)

WAN – Wide Area Network (takes support of X.25, Frame-relay, ATM, Internet, ISDN)

SoAN – Solaris Area Network (network using satellite)

WIRELESS

INTERNET

EXTRANET – Connection between different branches

INTRANET – Connection within the branches

LAN Requirements for Networking:

Server, Client, NIC, Cable (Media), Switch, Topology, Protocol, Services.

Media:

There are 2 types of media

1.Guided media (wired media) 2.UnGuided media (wireless media)

1.Guided media (wired media)

e.g. Co-axial cable, twisted pair cable, fibre optics cable

Co-axial cable

1.Maximum Distance 500mts

2.Low response

3.Less attenuation

4.Speed 10Mbps

5.Communication done is half duplex

6.Connection done using BNC – Bayonet Neil Concellmen Connector

7.Registered Guage Standard (RG)

RG 9,11,12 Thinnet Coaxial Cable

RG 58 Thicknet Coaxial Cable

RG 58/U, RG 58A/U Military Network

RG 59 Dish Network

RG 62 Arc Net

Thicknet also called as 10base5 where 10 – Bandwidth base – Baseband and 5 – 500mts

Thinnet also called as 10base2 where 10 – Bandwidth base – Baseband and 2 – 200mts

Twisted pair cable

1.Maximum Distance 100mts

2.Speed 10/100/1000Mbps

3.Communication done is half / full duplex

4.Connection done using RJ45 Connector

10baseT Supports 10Mbps

10baseTx Supports 10 or 100 Mbps

100baseT Supports 100Mbps

1000baseTx Supports 1Gbps

4 pairs of wires, orange – tip orange/white – tap.

All orange/white, green/white, blue/white, brown/white provides grounding to the orange, green, blue, brown wires.

Types of Twisted pair cable

1.Unshielded Twisted Pair Cable (UTP) 2.Shielded Twisted Pair Cable (STP)

Categories of Twisted pair cables

CAT1 Telephone Networks (4Mbps)

CAT2 Small Computer Networks, Telephone Networks (4Mbps)

CAT3 LAN – Ethernet (16Mbps)

CAT4 Token Ring Network (40Mbps)

CAT5 LAN – Fast Ethernet (100Mbps)

CAT5e & CAT6 LAN – Fast Ethernet (1Gbps / 1000Mbps)

Registered Jack (RJ Connectors)

RJ11 Telephones

RJ12 Telephone Network, Modems, Small Networks

RJ45 Local Area Network

Optical Fibre Cable

1.Maximum Distance 3 to 10 Kms

2.No EMI – Electro Magnetic Interference

3.Speed 100Mbps or Higher

4.Connectors used are ST – Straight Trip and SC – Subscriber Connectors

5.Two modes of communication Single mode (single beam) and Multiple mode (multiple beam)

2.UnGuided media (wireless media)

e.g. infrared, microwaves, radio waves

Infrared

1.Introduced in 1985

2.Point-to-Point communication (distance between 2 computers should not be more than 15mts)

3.Multipoint communication (distance between 2 computers should not be more than 30 mts)

4.Maximum Bandwidth 11Mbps

Microwaves

1.Electromagnetic Waves > 1Mhz

Radio Waves

1.Introduced in 1998 for computers

2.Electromagnetic Waves < 1Mhz

3.Maximum frequency available now is 2Ghz

Protocols

A set of rules for a particular type of communication.

Two types of Protocols

1.Connection Oriented 2.Connectionless Oriented

Connection Oriented

1.Follows the same path for data transfer

2.Acknowledgement

3.Reliable

4.e.g. TCP, SPX, AppleTalk datagram protocol

Connectionless Oriented

1.Follows the path where less traffic is found

2.No Acknowledgement

3.Non-Reliable

4.e.g. IP, IPX, UDP, AppleTalk protocol

Standards

Two types of Standards

1.Defacto Standard 2.Dejuire Standard

Defacto Standard

Standard widely used by all is called as Defacto Standard.

Dejuire Standard

Standard defined by an organization is called as Dejuire Standard.

Standard Organizations / Committees

IEEE – Institute of Electrical and Electronics Engineers

IANA – International Assigned Number Authority

ISO – International Standards Organization

ITU-T – International Telecommunication Union – Telecommunication Standardization Sector

EIA / TIA – Electronics Industry Association / Telecommunication Industry Association

ANSI – American National Standards Institute

Network Segmentation

Breaking up a larger network into a number of smaller ones is called as Network Segmentation and is accomplished using Routers, Switches and Bridges.

Causes of LAN Traffic congestion

1.Too many hosts in a broadcast domain

2.Broadcast storms

3.Multicasting

4.Low Bandwidth

5.Adding Hubs for connectivity to the network

6.A large amount of ARP and IPX Traffic.

Broadcast Domain

A group of devices receiving broadcast frames initiating from any device within the group.

Collision Domain

The network area in Ethernet over, which frames that have collided and damaged.

Broadcast Storms

An undesired event on the network caused by the simultaneous transmission of any number of broadcasts across the network.

Multicasting

Any communication between a single sender and multiple receivers.

ARP

Address Resolution Protocol, the protocol that traces IP addresses to MAC addresses.

IPX

Internetwork Packet Exchange, layer 3 protocol used in Novell Netware networks for transferring information from servers to workstations.

Router

It’s a layer 3 device that connects 2 different networks and routes packets of data from one network to another. It breaks up Broadcast domain as well as Collision Domain.

Advantages of Router

1.Router don’t forward Broadcasts by default.

2.Perform access control on the traffic that flows through the router i.e. Packet Filtering.

3.Network Address Translation.

4.Quality of Service for particular network traffic.

5.Can be used as a DHCP relay agent.

7.Connects different VLAN’s.

DCE-Data Communications Equipment

The DCE supplies the physical connection to the network, forwards traffic, and provides a clocking signal to synchronize data transmission between DTE and DCE devices.

DTE-Data Terminal Equipment

Any device located at the end user i.e. network interface serving as a destination or source or both. DTE includes devices such as Multiplexers, routers, protocol translators and computers.

Different Modes for configuring a router

1.User Mode- some basic commands like ping, telnet can be done. Prompt will be Router >

2.Execution or Privilege or Enable Mode- can view all configuration details, minimal commands like ping, telnet, and clock setting. Prompt will be Router #

3.Global Configuration Mode- where all configurations are done. Prompt will be Router(config)#

Sub Configuration Modes

1.Interface configuration mode, prompt will be Router(config-if)#

2.Router configuration mode, prompt will be Router(config-router)#

3.Line configuration mode, prompt will be Router(config-line)#