Your Ad Here

Cisco CCNA 640-802 Tutorials Part-4

Filed under: , by: Network World

Importance of the levels of privilege in the Cisco IOS

Cisco IOS offers 16 privilege levels ( 0-15) for access to different commands or to make your router more secure.

The higher your privilege level mean the more router access you have and vice versa.

But most users or network administrators are familiar with only two privilege levels:

  • User EXEC mode—privilege level 1
  • Privileged EXEC mode—privilege level 15

or

  • privilege level 0 — Includes the disable, enable, exit, help, and logout commands.

  • privilege level 1 — Normal level on Telnet; includes all user-level commands at the router> prompt.

  • privilege level 15 — Includes all enable-level commands at the router# prompt.


By default you are in user EXEC mode (level 1) When you log in to a Cisco router.In this mode, you have access to limited information about the router, such as the status of interfaces, and you can view routes in the routing table. However, you can't make any changes or view the running configuration file.

By typing enable command takes you to level 15, privileged EXEC mode. In the Cisco IOS, In other words, you have full access to the router.

In bigger organization to properly manage and secure the router , Cisco gives the idea of levels

Configure the Levels

  • Show privilege: This command displays the current privilege. Here's an example:
router# show privilege
Current privilege level is 3
  • Enable: this command used to go to privileged EXEC mode. However, it can also take you to any privileged mode. Here's an example:
router# show privilege
Current privilege level is 3
router# enable 1
router> show privilege
Current privilege level is 1
router>
  • User: While this command configures users, it can also tell the IOS which privilege level the user will have when logging in. Here's an example:
router(config)# username test password test privilege 3
  • Privilege: This command configures certain commands to be available only at certain levels. Here's an example:
router(config)# enable secret level 5 level5pass
  • Enable secret: By default, this command creates the password to get to privilege mode 15. However, you can also use it to create passwords to get into other privilege modes that you create.

CISCO Certification Exams Guides

Filed under: , by: Network World

640-802 CCNA Exam Guide

Exam Number: 640-802 CCNA

Associated Certifications: CCNA

Duration: 90 Minutes

Questions: (50-60 questions)

Cisco Career Certification exams include the following test formats:

  • Multiple-choice single answer
  • Multiple-choice multiple answer
  • Drag-and-drop
  • Fill-in-the-blank
  • Testlet
  • Simlet
  • Simulations

Exam Description:

The 640-802 Cisco Certified Network Associate (CCNA) is the composite exam associated with the Cisco Certified Network Associate certification. Candidates can prepare for this exam by taking the Interconnecting Cisco Networking Devices Part 1 (ICND1) v1.0 and the Interconnecting Cisco Networking Devices Part 2 (ICND2) v1.0 courses. This exam tests a candidate's knowledge and skills required to install, operate, and troubleshoot a small to medium size enterprise branch network. The topics include connecting to a WAN; implementing network security; network types; network media; routing and switching fundamentals; the TCP/IP and OSI models; IP addressing; WAN technologies; operating and configuring IOS devices; extending switched networks with VLANs; determining IP routes; managing IP traffic with access lists; establishing point-to-point connections; and establishing Frame Relay connections.

Cisco CCNA 640-802 Tutorials Part-3

Filed under: by: Network World

The Way to Configure the IOS Device i-e Router,Switch,PIX etc

Cisco’s routers and switches support two types of external connections

  • Ports(Also known as lines)
  • Interfaces.
Physical ports are used for management purposes and they do not effect the router traffic passing through the router.Every Cisco router and switch has a console (con) port; some have an auxiliary (aux) port.

Interfaces are used to connect networking devices together or for passing the network traffic, such as a switch and router or a switch and a PC. Interfaces are connected to the back plane of the switch or router.

Interfaces can be used for management purposes, it might affect the performance of your IOS device.

  • Console terminal
  • Cisco Works
  • Remote Terminal (aux port)
  • TFTP
  • Telnat
  • SSH
Console Terminal:
  • For Console port Connectivity to the PC you need a roll over cable
  • Configure the emulation software with the following settings
9600 baud
8 data bits
no parity
2 stop bits (9600 8N2) OR 1 stop bit Dependant on the router.

Cisco CCNA 640-802 Tutorials Part2

Filed under: by: Network World

Cisco Router or SWitch or Deivice Startup Process

Cisco Device goes to the following steps during the start up process

  1. POST
  2. Find and Load the IOS Software Image
  3. Find and Applies the Device Configurations


Important Information During Boot Process:


During First Phase as shown in the figure below

  1. Processor i-e. Series
  2. Main Memory Size
  3. IOS version Information



During Second Phase as shown in the figure below

  1. Information about the Interfaces
  2. Interfaces count
  3. Lines

Cisco CCNA 640-802 Tutorials Part1

Filed under: by: Network World

Cisco IOS basics

Cisco separates EXEC sessions into two access levels

  1. User EXEC mode (Also Known as USER MODE)
  2. Privileged EXEC mode( Also Known as ENABLE MODE)
User EXEC Mode:
It is represented by greater than ">" and has limited access and used to see the statistics only.user cannot change the configuration in this mode.This is first mode when you log in to the router.

Routername>

Privileged EXEC mode
:
It is represented by greater than "#" and you can change the configuration in this mode.

Routername#


How to enter or Exit from the privileged mode:

Routername>enable
Routername#

OR

Routername#disable
Routername>

Network Security

Filed under: , , by: Network World

What is Network Security:

Network security involves all activities or actions that organizations, enterprises, and institutions undertake to protect the value and ongoing usability of assets like data and the integrity and continuity of operations like queries.

An effective network security strategy requires

  • Identifying the nature of the threats
  • Choose effective set of tools to effectively remove the threats .
Network Security covers how to secure the network from external and internal attacks

External Attacks:
External to the company or organization or network

Internal Attacks:

From within the company network might be intentional or unintentional

Threats to Network Security

  • Insecure network Architectures
  • Broadcast Networks
  • Centralized Servers (Single point of failure)
  • Unused Services and Open Ports
  • Inattentive Administration
  • Inherently Insecure Services like inherent OS or application

How to Set Password on Console , AUX and VTY lines

Filed under: , by: Network World

Password set to Console mode

Router>enable
Router#configuration terminal
Router(config)#line console 0
Router(config-line)#password *****
Router(config-line)#login

Password set to Auxiliary port

Router>enable
Router#configuration terminal
Router(config)#line aux 0
Router(config-line)#password *****
Router(config-line)#login

Password set to Vty (Virtual Teletype-TELNET)


Router>enable
Router#configuration terminal
Router(config)#line vty 0 4
Router(config-line)#password *****
Router(config-line)#login

How To Configure the Static and Default route

Filed under: by: Network World

Configuration Static Routing


Router(config)#ip route Destination_network Mask Next-Hop_Address (or)
Router(config)#ip route Destination_network Mask Exit interface


Configuration Default Routing

Router(config)#ip route 0.0.0.0 0.0.0.0 Next-Hop_Address
Router(config)#ip route 0.0.0.0 0.0.0.0 Exit interface

How to view Router Information

Filed under: , by: Network World

View IOS version Router# show version
View current configuration file (RAM) Router# show running-config

View saved configuration file (NVRAM) Router#

show startup-config
View IOS version, size of IOS, and free space in FLASH Router# show flash
View CPU utilization Router# show processes cpu

View info about programs in RAM Router#

show processes
Display interfaces on router and their status Router# show interface
Display the ip interfaces on router and their status Router# show ip interface
Display which protocols are configured on the router Router# show protocol

Display ip protocol info Router#

show ip protocol

Getting Start With Router Basic Commands

Filed under: by: Network World

To get to User Mode Press ENTER and a password if required.
To get to Privileged Mode Router> enable
To get back to User Mode Router# disable
To Exit the Router Router> exit or logoff
Break Key

<shift>+<ctrl>+6 x

To move to the beginning of the command line Ctrl+A
To move to the end of the command line Ctrl+E
To move forward one character Ctrl+F [or right arrow key]
To move back one character Ctrl+B [or left arrow key]
To repeat the previous command Ctrl+P [or up arrow key]
To repeat the most recent (last) command Ctrl+N [or down arrow key]
To move back one word Esc+B
To move forward one word Esc+F
To erase a word Ctrl+W
To erase a line Ctrl+U
To redisplay a line Ctrl+R
Ends configuration mode and returns to privileged mode Router# Ctrl+Z
To auto complete a command <tab>
To show the command buffer Router> show history
To set the command buffer size Router> terminal history size
To disable advanced editing features Router> terminal no editing
To re-enable advanced editing features Router> terminal editing

How to Choose a Cisco router that best fits your organization's needs

Filed under: , by: Network World

Performance
Performance means how many packets per second the router could forward. For example, a Cisco 2600 series routers can forward an estimated 15,000 packets per second

Feature Upgradability

Router processors are rarely upgradeable, so this concerns to RAM and Flash.

Feature Expandability
Number of WAN and LAN interfaces supported by the router.

Software features
For example, you might need a router to support a certain interfaces for future or features like VOIP,QOS etc

Integrated services
This refers to functionality supported by a router that previously required separate boxes. For example, by adding a 16- or 32-port switching module in a router negates the need for an Ethernet switch; having a firewall, VPN server, and IDS/IPS sensor in a router can negate the need for a firewall, VPN concentrator, and dedicated IDS/IPS appliance.

Manageability
The router supports GUI interface, or is it command line only? Is there an interface available that allows you to manage multiple routers.

Redundancy
Redundancy is a critical feature for the network? Redundancy examples include hot-swappable power supplies or high-availability routing protocols such as HSRP or VRRP.

Support and reliability

Cisco traditionally offers a high level of support.

Cisco Switching Products Types

Filed under: , by: Network World

Cisco offers two types of network switches

  • Modular switches
  • Fixed-configuration switches

Modular Switches

Cisco Catalyst modular network switches provide operational simplicity, media flexibility, and expandability to extend deployment life and reduce total ownership costs. Cisco switch products offer high availability, integrated security, strong support for converged applications, and significant long-term investment protection.

Fixed Configuration Switches

Cisco Catalyst fixed-configuration network switches offer exceptional performance, reliability, and serviceability in models for a wide variety of organization sizes.


Cicso Interview Questions with Answers

Filed under: , by: Network World

Router Types:


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

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

2.UnGuided media (wireless media)


e.g. infrared, microwaves, radio waves,Infrared

View ACL Statistics in Cisco router or Switch

Filed under: , by: Network World

Objectives:

Which ACLs are being used.
How many times an ACL entry (ACE) was used and on which interface.

Router# show access-lists ?
  <1-2699>           ACL number
  WORD               ACL name
  compiled           Compiled access-list statistics
  rate-limit         Show rate-limit access lists
  |                  Output modifiers
  

By number:


Router# show access-list 158

Extended IP access list 158

10 deny ip any any time-range denytime (active) (65951975 matches)


By name:


Router# show access-list MyACL
Extended IP access list MyACL
    10 permit tcp host 21.35.80.22 eq telnet host 21.23.77.101
    20 permit tcp host 21.35.80.25 eq 16100 host 21.23.77.101 (149407

Access-lists per interface and per direction:

Input ACL-

Router# show ip access-list interface FastEthernet 0/1 in Extended IP access list 150 in 10 permit ip host 10.1.1.1 any (3 matches) 30 permit ip host 10.2.2.2 any (12 matches)

Output ACL-

Router# show ip access-list interface FastEthernet 0/0 out Extended IP access list myacl out 5 deny ip any 10.1.0.0 0.0.255.255 10 permit udp any any eq snmp (6 matches)

New CCNA Level Exams

Filed under: by: Network World

Cisco introduce the CCNA Security, CCNA Voice, and CCNA Wireless concentrations–the smart way for individuals to establish a deeper level of expertise in these three important areas of Cisco network technology because future lies in Security , Voice and Wireless.

CCNA Price Increase

Filed under: by: Network World

Cisco will be INCREASING the price of the CCNA 640-802 exam from $150 to $250! The price for the ICND 1 and ICND 2 exams will remain $125

Wireless LAN Standard including G and N

Filed under: , by: Network World

Standard Frequency Max Data rate Indoor Range Outdoor range

802.11A 5GHz 54Mbps 35 Meters 120 Meters


802.11B 2.4GHz 11Mbps 38 Meters 140 Meters


802.11G 2.4GHz 54Mbps 38 Meters 140 Meters


802.11N 2.4GHz 248Mbps 70 Meters 250 Meters

Administrative Distance

Filed under: by: Network World

The Administrative Distance (AD) is used to rate the trustworthiness of routing information received on a router from a neighbor router.

An Administrative Distance is an integer from 0 to 255, where 0 is the most trusted and 255 means no traffic will be passed via this route.

If a router receives two updates listing he sane remote network, the first thing the router checks is the AD. If one of the advertised routes has lower AD than the other, then the route with the lowest AD will be placed in the routing table.

If both advertised routes to the same network have the same AD, then routing protocol metrics (such as hop count or bandwidth of the lines) will be used to find the best path to the remote network. The advertised route with the lowest metric will be placed in the routing table.
But if both advertised routes have the same AD as well as the same metrics, then the routing protocol will load-balance in the remote network

Dynamic Routing

Filed under: by: Network World

Dynamic routing is when protocols are used to find networks and update routing table on routers.

A routing protocol defines the set of rules used by router when it communicates routing information between neighbor routers

There are two type of routing protocols used in internetworks:

Interior Gateway Protocols (IGPs)

IGPs are used to exchange routing information with routers in the same Autonomous System(AS) number.

Exterior Gateway Protocols (EGPs)

EGPs are used to communicate between different Autonomous System.

Autonomous System.

An autonomous system is a collection of networks under a common administrative domain, which basically means that all routers sharing the same routing table information are in the same AS.

Routing Protocol Basics.

Administrative Distances

Routing protocol

Routing Loops

Cisco Router Components

Filed under: by: Network World

ROM (Read-Only Memory) ­

Hosts the basic commands of the router and sometimes a limited version of the IOS (Internet Operating System). ROM is non- volatile, meaning it is hard-coded and does not change. Contains power-on diagnostics, a bootstrap program, and operating system software.

RAM (Random Access Memory)
­
Contains the running version of the IOS and the current running configuration. This is extremely volatile; when the router is shutdown, anything in RAM is lost. Stores routing tables, ARP cache, fast-switching cache, packet buffering (shared RAM), and packet hold queues.

NVRAM (Non-Volatile Random Access Memory)

As the name implies, files can be written to this memory and will not be lost when the system is powered down. This is where the startup version of the router configuration is stored.

Flash memory (EEPROM ­ Electronic Erasable Programmable Read Only Memory) ­

This is where the IOS version for the router is stored. It is important when determining what version of IOS to load on a router, that you ascertain how much flash is installed. Different versions of IOS require more flash to be loaded. Flash memory holds the operating system image and microcode.