network fundamentals: ch11 - configuring and testing your network

Suez Canal University – Faculty of Computers & Informatics - Cisco Local Academy

Network Fundamentals

CH11: CONFIGURING AND TESTING YOUR NETWORK

Abdelkhalik Elsaid Mosa

[email protected]

http://abdelkhalik.staff.scuegypt.edu.eg/


What is a Router?

• Front View

• Rear View


What is a Router?

Router is a computer which consists of

H/W S/W

CPU InterfacesMemory IOS Config File

Flash NVRAM RAM ROM LAN WANManagement


Router’s Memory

• RAM «volatile»: used to store1. Running version of IOS.2. Running config. File.3. Routing table.4. ARP Cache «is used on routers that have LAN interfaces».5. Packet Buffer.

• ROM «permanent»: used to store1. POST, Basic diagnostic software.2. Bootstrap.3. Scaled down Version of IOS «Rxboot».4. ROMMon.

• Flash «Non volatile»: used to store IOS.• NVRAM: used to store Start Up Configuration.


Router Boot-up Process


Router’s Interfaces

• Router Interfaces: capable of sending and receiving traffic. 1. LAN 2. WAN• Management Ports: used for administrative access.1. Console2. AUX


Cisco IOS - Access Methods

• The most usual methods are:1. Console: Doesn’t require active networking services.2. AUX port: Doesn’t require active networking services.3. Telnet or SSH: Requires active networking services.


Console Port

• Examples of console use are: The initial configuration of the network deviceDisaster recovery procedures and troubleshooting where

remote access is not possible.Password recovery procedures.


Using HyperTerminal

http://www.bbn.com/

http://www.bbn.com/


Auxilary Port


Cisco IOS Modes

• Cisco IOS is a Modal OS.• In order from top to bottom, the modes are:

1. Setup mode.2. User executive mode “view only mode”3. Privileged executive mode “enable mode”4. Global configuration mode5. Other specific configuration modes


Setup mode

• Permit admin to install a minimal configuration for a router.• The router will enter setup mode when:

Contents of NVRAM erased “erase startup” command. When the router is “out of the box”.

• You can make the router enter setup mode by entering: Router# setup


User executive mode

• Allows only a limited number of basic monitoring commands. • Often referred to as a “view only” mode. • Does not allow any commands that might change the

configuration of the router. • Identified by the > prompt.


Privileged executive mode

• Provides access to all router commands. • This mode can be configured to require a password. • Global configuration mode and all other more specific

configuration modes can only be reached from the privileged EXEC mode.

• The privileged EXEC mode can be identified by the # prompt.


Global configuration & Specific Configuration

• Configuration changes are made that affect the operation of the device as a whole.


Basic IOS command structure


Using CLI help

• The IOS has several forms of help available:1. Context-sensitive help2. Command Syntax Check3. Hot Keys and Shortcuts


Context-sensitive help


Command Syntax Check


Hot Keys and Shortcuts

• Tab: Completes the remainder of the command or keyword.• Ctrl-R: Redisplays a line• Ctrl-Z: Exits configuration mode and returns to the EXEC.• Down Arrow: Scroll forward through former commands.• Up Arrow: Scroll backward through former commands• Ctrl-Shift-6: Interrupt an IOS process such as ping or tracert.• Ctrl-C: Aborts the current command and exits the

configuration mode.• Abbreviated commands: Commands can be abbreviated to

the minimum number of characters that identifies a unique selection. Ex: sh int = show interfaces


IOS examination commands

• Show version• Show flash• Show interfaces• Show startup-config• Show running-config


Basic Router Configuration

• Naming the router: Host name should be unique.

• Banner: Banner should warn against unauthorized use.

• Passwords: Use strong passwords• Privileged mode password

• Console Password

• Telnet Password


Basic Router Configuration

• Interface configurations: interface type, IP address and subnet mask. Describe purpose of interface. Issue no shutdown command. If DCE serial issue clock rate command.


Configuring a serial interface

S0/0S0/1

192.168.1.1/30192.168.1.2/30

RouterA(config)# interface serial 0/0RouterA(config-if)# ip address 192.168.1.1 255.255.255.0RouterA(config-if)# no shutdownRouterA(config-if)# clock rate 56000 (required for serial DCE only)RouterA(config-if)# exit

RouterB(config)# int serial 0/1 RouterB(config-if)# ip address 192.168.1.2 255.255.255.252RouterB(config-if)# no shutdownRouterB(config-if)# exitRouterB(config)# exitRouter#

To know which interface is the DCE :RouterA# show controller s0/0


Interpreting the Interface Status

• Other Interface Status• Serial0/1 is administratively down , line protocol is down

interface is shut down • Serial0/1 is down , line protocol is down

interface or cable H/W failure ( no keep-alives )• Serial0/1 is up , line protocol is down

different encapsulation type ( PPP , HDLC , FR ) or no clock rate on DCE.

Layer 1 status Layer 2 status

Interface is working properly


Just Refresh – Enable Mode commands

• copy running-config startup-config• copy startup-config running-config• erase startup-config• ping ip_address• traceroute ip_address• show interfaces• show version• show arp• show startup-config• show running-config• show ip interface brief • configure terminal• show controllers serial_interface


Thank You..

network fundamentals: ch11 - configuring and testing your network

Technology

global configuration

router commands

privileged executive

privileged exec mode

initial configuration

minimal configuration

user executive mode

specific configuration