Chapter One

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Cisco Devices

The chapter walks you through the requisite information and commands needed to connect rollover cables to the switch or router. The chapter also spans around the determination of the terminal settings and setup of LAN connections. I have explained different categories in bullets to give you a clear understanding.

Cable Types

You must ensure that the cabling is properly done or you might trigger problems before you even start. See the following pattern.

• If your device A contains a computer COM port and device B contains the console of switch or router, you should use the rollover cable.
• If your device A contains computer NIC and device B contains the switch or hub, you should use the straight-through cable.
• If your device A contains computer NIC and device B also contains computer NIC, you should use the crossover cable.
• If your device A contains computer NIC and device B also contains computer NIC, you should use the rollover cable.
• If your device A contains a switch or hub port and device B contains Router’s Ethernet port, you should use the straight-through cable.
• If your device A contains a switch or hub port and device B also contains a switch or hub port, you should use the crossover cable. Also, don’t forget to check for the uplink button to defeat this.
• If your device A contains a router’s Ethernet port and device B also contains a router’s Ethernet port, you should use the crossover cable.
• If your device A contains a router’s serial port and device B also contains a router’s serial port, you should use the Cisco serial DCE/DTE cable.
• If your device A contains a computer NIC and device B contains the router’s Ethernet port, you should use the crossover cable.

Different cables have different pinout systems. See the following patterns.

Crossover Cable: Pin 1 – Pin 3, Pin 2 – Pin 6, Pin 3 – Pin 1, Pin 4 – Pin 4, Pin 5 – Pin 5, Pin 6 – Pin 2, Pin 7 – Pin 7, Pin 8 – Pin 8

Straight-Through Cable: Pin 1 – Pin 1, Pin 2 – Pin 2, Pin 3 – Pin 3, Pin 4 – Pin 4, Pin 5 – Pin 5, Pin 6– Pin 6, Pin 7 – Pin 7, Pin 8 – Pin 8

Rollover Cable: Pin 1 – Pin 8, Pin 2 – Pin 7, Pin 3 – Pin 6, Pin 4 – Pin 5, Pin 5 – Pin 4, Pin 6 – Pin 3, Pin 7 – Pin 2, Pin 8 – Pin

LAN Connections

• If the connection or port is Ethernet, the port type will be RJ-45. You must connect it to an Ethernet hub or Ethernet switch through cable RJ-45.
• If the connection or port is TI/EI WAN, the port type will be RJ-48C/CA81A. You must connect it to EI or TI network through rollover cable.
• If the connection or port is a console, the port type will be 8-pin. You must connect it to a computer COM port through rollover cable.
• If the connection or port is AUX, the port type will be 8-pin. You must connect it to the Modem through cable RJ-45.
• If the connection or port is BRI U WAN, the port type will be RJ-49C/CA11A. You must connect it to an ISDN network exchange (PINX) through cable RJ-45.
• If the connection or port is BRI S/T, the port type will be RJ-48C/CA81A. You must connect it to an NTI device or private integrated network exchange (PINX) through cable RJ-45.

The Difference Between 568A and 568B Cables

Two standards have been released by EIA/TIS group about the UTP wiring. These are dubbed as 568A and 568B. 568B is a bit newer and it is the standard. The difference between the two standards is due to the pin assignments and not based on the type of colors. The 568A standard is greatly compatible with the United States’ Universal Service Order Codes (USOC) standards for the telephonic infrastructure and the voice connections. In both standards, the orange and blue pairs are at the center four pins therefore these colors tend to match closely with the 568A. It is best practice to use 568A for new installations and 568B for the existing installations. Now let us analyze the 568A and 568B standards.

568A Standard

• Pin 1 of white or green color will pair with 3. Its description is RecvData +.
• Pin 2 of green color will pair with 3. Its description is RecvData -.
• Pin 3 of white or orange color will pair with 2. Its description is TxData +.
• Pin 4 of blue color will pair with 1. Its description is ‘Unused’.
• Pin 5 of white or green color will pair with 1. Its description is ‘Unused’.
• Pin 6 of orange color will pair with 2. Its description is TxData .
• Pin 7 of white or brown color will pair with 4. Its description is Unused.
• Pin 8 of brown color will pair with 5. Its description is Unused.

568B Standard

• Pin 1 of white or orange color will pair with 2. Its description is TxData +.
• Pin 2 of orange color will pair with 2. Its description is TxData +.
• Pin 3 of white or green color will pair with 3. Its description is RecvData +.
• Pin 4 of blue color will pair with 1. Its description is Unused.
• Pin 5 of white or blue color will pair with 1. Its description is Unused.
• Pin 6 of green color will pair with 3. Its description is RecvData -.
• Pin 7 of white or brown color will pair with 4. Its description is Unused.
• Pin 8 of brown color will pair with 4. Its description is Unused.

The odd pin numbers always belong to the striped wires.

Command Line Interface

To enhance efficiency, Cisco IOS software has provided the users with some shortcuts to enter the most used commands.

• The command Router>enable is the same as Router>enab and Router>en. When you enter the short form of the commands, it is fine as long as you have no confusion.
• The command Router#configure terminal can be used interchangeably with Router#config t.
• You also can use the tab key to execute the commands. The command Router#sh + Tab key is the same as Router#show.

The question mark plays an important role in executing commands. You can use the question mark to see what you can do with the command and its parameters.

Question Mark

• The command Router#? will list all the commands that are available in the present command mode.
• The command

Router#c?

clear clock

will list all the available choices that tend to start with c.

• The command

Router#c1?

clear clock

will list all the available choices that will start with cl.

• The command

Router#clock ?

set

will list all the available choices that reveal all the subcommands that are linked to this command. It also sets the date and time of the system.

• The command Router#c?  set 20:40:00 17 August 2020 ? + Enter key will confirm that you have configured the data and time of the system.
• The command Router# will show there is no incomplete command message or error message and that the command was executed successfully.

Miscellaneous Commands

• There is an enable command you can use to move the user. The command Router>enable Router# will move the user to the privileged mode.
• The command Router#exit or Router>exit allows the user to log off on the system.
• The command Router(config-if)#exit Router(config)# will move the user back to level one.
• The command Router(config)#exit Router# will also move the user back to level one.
• The command Router#disable Router> will move a user from the privileged mode to the user mode. It is known as the disable command.
• The command Router#logout has the same function to perform as exit. It is known as the logout command.
• The command Router#setup will take the user to the startup mode right at the command line. It is labeled as the setup mode and you will see an answer in the square brackets. If this is what you want, you should go on and press the Enter key. If you want to end the setup process at any point, you can enter Ctrl + C to shut down the interfaces and return to the user-mode Router>. The setup mode can never be used for the router's configuration as it only performs the basics. You can turn on the IGRP or RIPv1 but not the EIGRP or OSPF and you cannot make ACLs or enable the NAT.

Keyboard Usages

You can use different keyboard commands during the editing process. There will be many tasks that you will repeatedly be using. To make it possible, the Cisco IOS Software allows you to use different keyboard combinations to make the process highly efficient.

• You can use the carrot symbol ^ over the 6 key on the keyboard to locate the mistake you might have made while entering the command.
• You can enter ctrl + a on the keyboard to move the cursor from where it is to the start of the line.
• You can enter ctrl + b on the keyboard to move the cursor from where it is to the back by one word.
• You can enter ctrl + b or the left arrow on the keyboard to move the cursor from where it is to back by one character.
• You can enter ctrl + e on the keyboard to move the cursor from where it is to the end of the line.
• You can enter Esc + f on the keyboard to move the cursor from where it is to a forward point by one word.
• You can enter Ctrl + f or the right arrow on the keyboard to move the cursor from where it is to a forward point by one character.
• You can enter $ that is above the 4 key on the keyboard to indicate that you have scrolled the line toward the left side.
• You can enter Router#terminal no editing to turn off the ability to use the keyboard shortcuts of the previous session.
• You can enter Router#terminal editing to re-enable the enhanced editing mode.

You can scroll through the history by the following commands.

• You can enter Ctrl + P or the up arrow on the keyboard to recall the commands that you have used in the past and that are a part of history. You will be able to use them in the backward sequence. You will see the most recent command.
• You can enter Ctrl + P or the up arrow on the keyboard to recall the commands that you have used in the past and that are a part of history. You will be able to use them in the backward sequence. You will see the most recent command.
• You can enter Ctrl + n or the down arrow on the keyboard to return the commands that you have used most recently.
• You can enter terminal history size number to set the total number of commands that reside in the buffer and that the router can recall. For example, Router#terminal history size 30 will recall the last 30 commands that are in the buffer. Similarly, the command Router#no terminal history size 25 will set the history buffer coming back to the last ten commands. This is the default view of the command line. The history size command helps provide the function as that of the terminal history size command.

You can apply some show command to scan the information about the command line interface and the systems.

• The command Router#show version will display the requisite information about the present IOS.
• The command Router#show history will display all the commands you have used in the command line interface history.
• The command Router#flash version will display the requisite information about the flash memory of the system.

The last line of output from the show version tells us what the configuration register has been set up to.