1. Configuring a network os
Chapter 2
Intro to Routing & Switching

2. Objectives Upon completion of this chapter you will be able to:
Explain the purpose of Cisco IOS.
Explain how to access and navigate Cisco IOS to configure network devices.
Describe the command structure of Cisco IOS software.
Configure hostnames on a Cisco IOS device using the CLI.
Use Cisco IOS commands to limit access to device configurations.
Use Cisco IOS commands to save the running configuration.
Explain how devices communicate across network media.
Configure a host device with an IP address.
Verify connectivity between two end devices.
Explain to the students that this chapter will cover four basic concepts required for setting up and testing a network.
The first is what you need to know before you configure devices. This involves knowing the functions of the Internetwork Operating System found on most Cisco devices, learning to communicate with the IOS using the Command Line Interface (CLI) and physically connecting to the devices.
The second is knowing the basics of device configuration including securing the device, naming devices, and enabling interfaces so the device can become more than a big box.
The third is knowing the basic tools for verifying network connectivity such as ping and traceroute; and finally, the need for and how to monitor and document a network.

3. Your home network Home routers are actually four devices in one:
Router- Forwards data packets to and receives data packets from the Internet
Switch- Connects end devices using network cables
Wireless access point- Consists of a radio transmitter capable of connecting end devices wirelessly
Firewall appliance- Secures outgoing traffic and restricts incoming traffic

4. Business network
Larger network has more traffic. Usually have many separate devices, although some still combine. Here we have separate switches, access point, and router. Each device performs a particular job. The switch, router, and WAP are what kind of network devices? Intermediary devices. They transport data.
All of these devices use an OS. On Cisco, it’s called an IOS. The IOS is configurable and has different features.

5. 2.1.1
Cisco ios

6. ios Cisco Internetwork Operating System (IOS)
On all Cisco devices
Stored on flash/flash memory card
Non-volatile
Stays w/out power
Can be overwritten & upgraded
When powered, copied from flash & runs in RAM
Multiple IOSs can be on flash.
Different versions of IOS, depending on the device & features included. To upgrade you need to know how much flash & RAM memory is needed, device model #, and features you want/need.
Major functions performed or enabled by Cisco routers and switches include:
Providing network security
IP addressing of virtual and physical interfaces
Enabling interface-specific configurations to optimize connectivity of the respective media
Routing
Enabling quality of service (QoS) technologies
Supporting network management technologies

7. Accessing the ios Take a look at the router
How do you think we can access the IOS?
You want them to explain the device can be accessed via the console port (a direct physical connection) or via Telnet, SSH (a remote virtual connection), HTTP (web), or via AUX (telephone modem or ISDN).
Keep the device in a secure location too!

8. 2.1.2
Accessing the ios

9. Console Port Out-of-band management
Means direct maintenance access only
Can access when nothing is configured yet
Need a computer w/ terminal emulation software & console cable
Assign a password to it!
There is a recovery method if you forget password.

10. Telnet, ssh, aux Telnet Secure Shell (SSH) Aux Port Remote access
Plain-text password
One active interface must be configured
Secure Shell (SSH)
Remote access w/ encryption
Aux Port
Out-of-band connection/maintenance
Uses telephone line
Can be used like console port
Once you connect, you get in with a terminal emulation program. Current Windows (Vista & up) do not include them Older Windows had HyperTerminal.
PuTTY (Figure 1)
Tera Term (Figure 2)
SecureCRT (Figure 3)
HyperTerminal
OS X Terminal

11. Activity

12. review What does IOS stand for?
Internetwork Operating System
Where is the IOS stored on a Cisco router & switch?
In flash memory
When a router or switch boots up, it loads the IOS from where to where?
Flash to RAM
What port will you most likely connect to for 1st time config & direct maintenance?
Console
Homework: Watch the video on

13. 2.1.3
Navigating the ios

14. modes Begin by writing the major modes on the board:
User executive mode
Privilege executive mode
Global configuration mode
Interface, router, & line configuration modes as well
Define each & write out the prompts.
Display a router interface and demonstrate the modes and their associated prompts. Also demonstrate how to back out from privilege EXEC to user EXEC with the “disable” command. Next demonstrate the various forms of context- sensitive help available.
Know what the prompts look like! How to get into each prompt & how to get out, too.

15. This is CLI!

16. User & privileged modes
USER is what you first see when you boot up.

17. Global config mode

18. Getting between modes Router> enable (en)
Router# configure terminal (config t)
Router (config)# interface xxx (int)
Router (config-if)#
Router (config-line)#exit (goes back one mode)
Ctrl+Z or end= takes back to privileged
Switch# disable (goes back to user)
Do all of this in PT. Demo all modes, sh?, cl?, clock set ?, clock set 19:22:00 ?, show ?, description of an interface, ping, and traceroute

19. review

20. Oops…I made a mistake

21. shortcuts
Tab - Completes the remainder of a partially typed command or keyword
Ctrl-R - Redisplays a line
Ctrl-A – Moves cursor to the beginning of the line
Ctrl-Z - Exits configuration mode and returns to user EXEC
Down Arrow - Allows the user to scroll forward through former commands
Up Arrow - Allows the user to scroll backward through former commands
Ctrl-Shift-6 - Allows the user to interrupt an IOS process such as ping or traceroute.
Ctrl-C - Aborts the current command and exits the configuration mode
Enter- displays next line
Space bar- displays next page
DEMO most of these.

22. Show commands Provide info only Different commands in different modes
show startup-config (show start)
Displays the saved configuration located in NVRAM.
show running-config (show run)
Displays the contents of the currently running configuration file.

23. Show version Software version - IOS software version (stored in flash)
Bootstrap version - Bootstrap version (stored in Boot ROM)
System up-time - Time since last reboot
System restart info - Method of restart (e.g., power cycle, crash)
Software image name - IOS filename stored in flash
Router type and processor type - Model number and processor type
Memory type and allocation (shared/main) - Main Processor RAM and Shared Packet I/O buffering
Software features - Supported protocols/feature sets
Hardware interfaces - Interfaces available on the device
Configuration register - Sets bootup specifications, console speed setting, and related parameters

24. Labs 2.1.4.8 2.1.4.9 Navigating the IOS Packet Tracer
Establishing a Console Session with Tera Term

25. Notes on terminal emulation
What are the settings in a terminal emulation program to access the CLI?

26. review

27. 2.2.1
Getting basic

28. What we’ll do… Create a two PC network connected via a switch
Setting a name for the switch
Limiting access to the device configuration
Configuring banner messages
Saving the configuration

29. Hostnames What are the default hostnames?
Hostnames allow devices to be identified by network administrators over a network or the Internet.
What could these switches be named? Sw-Floor1, etc.
Some guidelines for naming conventions are that names should:
Start with a letter (Capitalization counts)
Contain no spaces
End with a letter or digit
Use only letters, digits, and dashes
Be less than 64 characters in length

30. Configure hostname Must be in privileged mode
has activity to name a device

31. Limit access to device Secure location Set passwords
On the board, write the 4 types of passwords students will be learning to configure in the PT Activity.
console password – password to limit device access using the console connection
enable password – password to limit access to the privileged EXEC mode
enable secret password – encrypted password to limit access to the privileged EXEC mode
VTY password – password to limit device access using telnet

32. Password tips We’ll use cisco & class
Use passwords that are more than 8 characters
Use combination of upper & lowercase letters, numbers, special characters
Avoid using the same password for all devices
Avoid using common words such as password or administrator
Explain it is good practice to require different passwords for each of these levels of access. From a security standpoint, requiring only one password is analogous to locking the doors to a house while leaving the windows open. Additionally, remind students to use strong passwords that are not easily guessed. The use of weak or easily guessed passwords continues to be a security issue in many facets of the business world. Ask the class how many of them have passwords that breach these best practices. There likely will be quite a few, which illustrates how common the errors are.
END OF DAY 3

33. Set passwords In Packet Tracer, complete:
Privileged enable password (cisco)
Privileged enable secret password (class)
Console password (cisco)
VTY password (cisco)
Banner MOTD
Encrypt all passwords
Then verify all passwords are encrypted by show run
has an activity
MOTD often used for legal notification because it is displayed to all connected terminals.
Have students come up with a proper MOTD warning.
END OF DAY 3

34. Banner motd

35. Saving configurations
2.2.3
Saving configurations

36. Configuration files In a switch:
The startup configuration is removed by using the erase startup-config command.
To erase the startup configuration file use erase NVRAM:startup-config or erase startup-config at the privileged EXEC mode prompt:
Switch#erase startup-config
On a switch you must also issue the delete vlan.dat command in addition to the erase startup-config command in order to return the device to its default "out-of-the-box" configuration (comparable to a factory reset):
Switch#delete vlan.dat
Delete filename [vlan.dat]?
Delete flash:vlan.dat? [confirm]

37. lab 2.2.3.3 Configuring a Switch
You will perform basic switch configurations.
You will secure access to the command-line interface (CLI) and console ports using encrypted and plain text passwords.
You will also learn how to configure messages for users logging into the switch. These banners are also used to warn unauthorized users that access is prohibited.

38. activity
Write the definitions listed in bold below on the board and then ask the students to name the command.
show running-config (definition: shows the config file in RAM. This file will be immediately changed if you make any changes to the router).
show startup-config (definition: this file is in NVRAM and will become the running-config in the event of a power cycle).
copy running-config startup-config (definition: this copies the current configuration in RAM to NVRAM)
reload (definition: this will cause the device to reload the startup-config into RAM)
copy startup-config running-config (definition: this copies the configuration in NVRAM to RAM)
erase startup-config (definition: will cause the startup config to be erased).

39. review What mode do you need to be in to make configuration changes?
If you erase the startup-config, what else will you need to do in order to return the device to factory default?
Answer 1: (Answer: privilege EXEC. You would not want just anybody to be able to change the configuration files)
Answer 2: (Answer: reload, until that happens the router will still continue to function with its running-config)

40. 2.3
Addressing Schemes

41. Ip addressing All end devices have an IP address
IPv
4 octets
0-255 in each
Subnet mask is included with it
Router ports (physical & virtual) have IP addresses
A switch has an IP address for remote maintenance (this is a virtual interface)
On End Devices: IP, SM, Default Gateway (explain it is the way out of the network…the router port it connects to)
You can enter address or click OBTAIN AUTOMATICALLY (explain DHCP)
Each device needs a UNIQUE IP address. You will get a conflict message if you do.

42. Home network
If one device is on a different network, it will not communicate.

43. Configure switch address
Virtual interface
Allows remote access
Activity on
Complete this on PT

44. LAB 2.3.2.5 You will first perform basic switch configurations.
Then you will implement basic connectivity by configuring IP addressing on switches and PCs.
When the IP addressing configuration is complete, you will use various show commands to verify configurations and use the ping command to verify basic connectivity between devices.

45. testing Ping Remote device or device you connect to
PC to switch
PC to PC
tests TCP/IP on you

46. lab Build & configure a small network in Packet Tracer
Configure a switch & test it
END OF DAY 4

47. Review & study Complete the study guide handout
Take the quiz on netacad.com
Jeopardy review

48. summary In this chapter, you learned:
Services provided by the Cisco IOS accessed using a CLI
Accessed by the console port, the AUX port, or through telnet or SSH
Can make configuration changes to Cisco IOS devices
A network technician must navigate through various hierarchical modes of the IOS
Cisco IOS routers & switches use a similar IOS

49. summary Introduced the initial settings of a Cisco IOS switch device
Setting a name
Limiting access to the device configuration
Configuring banner messages
Saving the configuration

50. Configuring a network os
Chapter 2
Intro to Routing & Switching