Lab 1 Goals
● Connect to the switch using the console port
● View the boot process
● Basic commands
Lab Requirements
● PC
● Cisco console (rollover) cable
● Cisco Catalyst switch: 2950 or 2900-XL
Process
- Using the Cisco console cable, connect the PC COMM port to the switch console port. Make sure that your terminal program is configured for 8N1 (8 data bits, No stop bits, 1 parity bit).
- Power on the switch. Very soon, text should be displayed on your PC. If no text is displayed, review your PC COMM port configuration.
It is important to understand the boot sequence. You should observe it enough times to be familiar with the messages and what they mean. Below are some critical displays with explanations.
Loading the IOS
Loading "flash:/c2950-i6q4l2-mz.121-22.EA4.bin"...
########################################################################## [OK]
Restricted Rights Legend
Things to recognize:
1. The boot sequence loads IOS from Flash memory. This is true for all Cisco IOS devices.
2. The version of IOS being loaded (your version will probably be different).
3. The “#’s” indicate the load progress.
4. [OK] indicates that the IOS load was successful.
Hardware Summary
The boot process provides a summary of the hardware configuration of the switch, shown below.
Cisco WS-C2950-24 (RC32300) processor (revision C0) with 21039K bytes of memory.
Processor board ID FHK0610Z0WC
Running Standard Image
24 FastEthernet/IEEE 802.3 interface(s)
32K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address: 00E0.F928.5566
Motherboard assembly number: 73-5781-09
Power supply part number: 34-0965-01
Motherboard serial number: FOC061004SZ
Power supply serial number: DAB0609127D
Model revision number: C0
Motherboard revision number: A0
Model number: WS-C2950-24
System serial number: FHK0610Z0WC
Note the following information:
1. Switch model: WS-C2950-24
2. 24 FastEthernet/IEEE 802.3 interfaces – the number of interfaces or connections that the switch supports.
3. Memory 21039K (RAM), and 32K flash-simulated non-volatile configuration memory. Non-volatile memory is similar to a hard drive on a computer. It stores information to be used by the switch. The information is retained when the device is powered down. RAM is the same as RAM on a computer.
4. Base MAC address: 00E0.F928.5566 – All of Layer 2 switching is dependent on MAC addresses. Become familiar with the MAC addresses of all types of equipment.
If the switch has no saved, or startup, configuration, you may be prompted to enter initial configuration dialog. For now, enter "no." Messages may appear on the screen, but at some point, the messages will stop. Press Return to access the switch.
Notice that the prompt is “Switch>.” A prompt of “Switch>” usually means that the switch has not been configured, or more correctly, has the default (out-of-the-box) configuration. The “>” indicates that you are in User EXEC mode, the least powerful access mode. To view the commands available in User Exec mode, enter “?”.
User Exec mode is limited to protect the switch from unauthorized changes. A more powerful mode is supported by IOS: Privilege EXEC mode. In the next lab, we will set passwords to limit access to Privilege EXEC mode. For now, access Privilege Exec mode by using the “enable” command.
Switch>enable
Switch#
The prompt now has a pound sign: #. This indicates Privilege EXEC mode. If you are experienced with UNIX/Linux, it is similar to root access, which is also indicated by the pound sign. Privilege EXEC mode is usually called “enable mode” by experienced techs. It may be called either enable mode or Privilege EXEC mod on the exam. Enable mode supports all commands that are available in User EXEC mode, as well as many other commands. Display the commands available in Privilege EXEC mode by entering “?”. All access is available in Privilege Exec mode, including configuration commands.
Notice “–More—“ at the bottom of the display, indicating that additional information is available. To display the remaining information, use “Enter” to display one line at a time, or use the space bar to display one screen at a time. This process is used for all displays that are larger than one screen. Practice using both.
As indicated above, all techs need to understand switch and router configurations. This includes understanding a configuration and its function, but it is also means to recognized when a component has not been configured. The following exercise will display the configuration of a switch that has not been customized. Understand that all devices have a configuration, but the default configuration may lack critical features. The following commands are important, not only for the exam, but more importantly, for managing a Cisco network. Learn the commands and the information they produce.
Switch#show running-config
The following display may be slightly different in your switch, depending on the model and IOS version. However, you will see these same elements, but perhaps in a different part of the display.
Building configuration...
Current configuration : 863 bytes
!
version 12.1
no service password-encryption
!
hostname Switch
!
!
!
interface FastEthernet0/1
!
interface FastEthernet0/2
!
interface FastEthernet0/3
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
!
interface FastEthernet0/10
!
interface FastEthernet0/11
!
interface FastEthernet0/12
!
(Interfaces 13-24 omitted)
!
interface Vlan1
no ip address
shutdown
!
line con 0
!
line vty 0 4
login
line vty 5 15
login
!
!
End
Note the following:
- The hostname is Switch, which is the same as the prompt. The hostname value is the system prompt.
- The FastEthernet interfaces have no visible configuration. Actually, each has a configuration which are all automatic features. Issues such as automatic speed and duplex negotiation, as well as some trunk port negotiation values have been set, but are not displayed.
- Compare the Vlan1 interface with the FastEthernet interfaces. Unlike switch FastEthernet interfaces, the Vlan1 interface can be configured with an IP address, but has not been configured with one. The Vlan1 interface has also been shut down.
- The FastEthernet interfaces do not support IP addresses, and they have not been shut down.
- There are three entries for lines: con 0, vty 0 4, and vty 5 15. (You may not have vty 5 15 on your model.)
Console and vty lines are used to manage the switch. The connectivity is different but the access authority (what you can do) is the same for either type of connection.
● Con 0 is the console line. There is a single console port, con 0. It is a physical line.
● Vty lines are virtual tty, or terminal, connections. vty lines support remote connections, either telnet or ssh.
● There are 16 vty lines for this switch: 0 through 4, and 5 through 15, or actually line 0 to line 15. These define the number of simultaneous connections that can be made to the switch. 16 simultaneous telnet sessions can be established to this switch.
What's the difference between interfaces, lines and ports? “Port” is not officially a part of Cisco vocabulary, even though everyone says "ports" when talking about the console port or data interfaces, as in, “What port is it on?” The difference between an interface and a line is the type of data that the interface or line supports. An interface, such as interface FastEthernet 0/1, is used to transport user data, such as IP, HTTP, etc. Lines are used for device management. Summary: Interface = data, lines = management access.
Switch# show version
The “show version“ command will display the version of IOS installed on the switch (or router), but it will display more than just the IOS version. It will also display most of the information that was shown during the boot process:
(How long the system has been available)
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(22)EA4, RELEASE SOFTWARE(fc1)
Copyright (c) 1986-2005 by cisco Systems, Inc.
Compiled Wed 18-May-05 22:31 by jharirba
Image text-base: 0x80010000, data-base: 0x80562000
ROM: Bootstrap program is is C2950 boot loader
Switch uptime is 35 seconds
System returned to ROM by power-on (How the system was booted: power or system reload)
Cisco WS-C2950-24 (RC32300) processor (revision C0) with 21039K bytes of memory.
Processor board ID FHK0610Z0WC
Last reset from system-reset
Running Standard Image
24 FastEthernet/IEEE 802.3 interface(s)
32K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address: 000C.CF90.9B8A
Motherboard assembly number: 73-5781-09
Power supply part number: 34-0965-01
Motherboard serial number: FOC061004SZ
Power supply serial number: DAB0609127D
Model revision number: C0
Motherboard revision number: A0
Model number: WS-C2950-24
System serial number: FHK0610Z0WC
Configuration register is 0xF
You have seen most of this information before during the boot process. One piece of information that is available from the show version command is the method by which it was rebooted, and the amount of time that the switch has been up. In this situation, the switch was powered on:
Switch uptime is 35 seconds
System returned to ROM by power-on
If the switch is booted by using the reload command, the display would show
Switch uptime is 45 minutes
System returned to ROM by reload at 09:22:58 edt Sun Feb 28, 2009
Interface displays
The status of interfaces can be displayed individually, or a summary of the status of all interfaces can be displayed. Interface status and statistics are some of your most important troubleshooting tools. It is critical to understand this display.
Switch#show interface FastEthernet Fa0/1
Note: this display contains a lot of information, all of it relevant in different troubleshooting situations, but not all of it is relevant here. Sections of the display are not shown.
FastEthernet0/1 is down, line protocol is down (disabled)
Hardware is Lance, address is 0010.112b.e701 (bia 0010.112b.e701)
MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec,
. [Lines deleted]
956 packets input, 193351 bytes, 0 no buffer
Received 956 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
2357 packets output, 263570 bytes, 0 underruns
0 output errors, 0 collisions, 10 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
The interface status is shown in the first line. In this display, the interface is "down, down". The remaining lines at the end of the display are data volume and errors. This information is critical in many troubleshooting exercises.
The show ip interface brief command shows a summary of the status of all interfaces.
[Lines omitted]
Switch# show ip interface brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/1 unassigned YES manual down down
FastEthernet0/2 unassigned YES manual down down
FastEthernet0/3 unassigned YES manual down down
FastEthernet0/4 unassigned YES manual down down
FastEthernet0/5 unassigned YES manual down down
FastEthernet0/6 unassigned YES manual down down
FastEthernet0/7 unassigned YES manual down down
FastEthernet0/8 unassigned YES manual down down
FastEthernet0/9 unassigned YES manual down down
FastEthernet0/10 unassigned YES manual down down
FastEthernet0/11 unassigned YES manual down down
FastEthernet0/12 unassigned YES manual down down
Vlan1 unassigned YES manual administratively down down
In this display, all FastEthernet interfaces are "down, down". The status of the VLAN1 interface is "administratively down".
VLANs
VLANS will be discussed in significant detail in future labs, but each switch comes out of the box with VLAN 1.
Switch>show vlan
VLAN Name Status Ports
---- -------------------- --------- -------------------------------
1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4
Fa0/5, Fa0/6, Fa0/7, Fa0/8
Fa0/9,Fa0/10, Fa0/11,Fa0/12
Fa0/13,Fa0/14,Fa0/15,Fa0/16
Fa0/17,Fa0/18,Fa0/19,Fa0/20
Fa0/21,Fa0/22,Fa0/23,Fa0/24
1002 fddi-default active
1003 token-ring-default active
1004 fddinet-default active
1005 trnet-default active
VLAN Type SAID MTU Parnt RngNo BrdgeN Stp BrdgMode Trns1 Trns2
---- ----- ---------- ----- ------ ------ -------- ---- --------
1 enet 100001 1500 - - - 0 0
1002 enet 101002 1500 - - - 0 0
1003 enet 101003 1500 - - - 0 0
1004 enet 101004 1500 - - - 0 0
1005 enet 101005 1500 - - - 0 0
All FastEthernet interfaces are in VLAN1, which is indicated as the default VLAN. The VLANs 1002-1005 are also default VLANS with a special purpose. If you are not familiar with VLANs, they will be covered in future labs.
Using Cisco IOS Commands
If you are just starting with Cisco IOS, you may feel that the commands are long and tedious. To help with that problem, Cisco has written the IOS to accept abbreviated commands as long as the commands are unique; that is, they cannot be confused with another command. You only have to enter enough letters to uniquely identify the command.
For example, we used the enable command above. What is the shortest command possible for enable? If the letter “e” is entered (the smallest number of letters possible), the switch returns the following:
Switch#e
% Ambiguous command: "e"
Why is “e” ambiguous? Other commands start with “e” and the switch does not know which one you want. To find the other commands that begin with “e”, enter
(no space between “e” and ?)
Switch#e?
The switch returns
Switch#e?
enable erase exit
• "en" is unique for "enable"
• "er" is unique for "erase"
• "ex" is unique for "exit"
There is no magic formula for determining the smallest number of characters that make a command unique. A command that you will be using very often in these labs is the “configure terminal” command. What is the smallest number of characters for this command? Find out by using “c?”, “co?”, “con?”. You find that the smallest number of characters needed to make the configure command unique is “conf”. Test for the shortest number of characters for “configure terminal” by using “conf t?” (no space after “t”). Terminal requires only “t”, because the only command that follows “configure” that begins with “t” is “terminal.”
Every command can be abbreviated. You will develop a set of abbreviations that you are comfortable with as you work with IOS devices.
Another use of the “?” is to find the qualifiers for a particular command. For example, the options for the configure command can be displayed by
(space between configure and “?”)
Switch#configure ?
terminal Configure from the terminal
The options for configure are “terminal” and carriage return(cr) (or Enter). Using (cr) will produce the following
Configuring from terminal, memory, or network [terminal]? Enter configuration commands, one per line. End with CNTL/Z.
"Terminal" is the default, but you can also configure from "memory" or "network."
A final thing to understand about commands is that a command can be completed by using the tab key. Enter “conf” and press tab, and the switch will complete the command as “configure.” Practice these commands to begin to develop your Cisco “keyboarding” skills.
Lab 2 will configure your switch with a basic configuration.
