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DEMO: Connecting to Equipment

Establishing a console connection to a Cisco device requires a rollover cable, a USB-to-serial adapter, and a terminal emulator configured to the correct COM port and baud rate. This process covers hardware identification, driver verification through Device Manager, PuTTY installation, and completing a live serial session to access the device CLI.

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About this video

Out-of-band console access is the standard method for configuring network devices that have not yet been set up for remote management. The physical connection relies on a rollover cable — distinguishable by its pin-reversal wiring — with an RJ45 end that plugs into the device's console port and a USB end that connects to the technician's laptop. Because RS-232 serial ports are largely absent from modern computers, a USB-to-serial adapter bridges the gap, and Windows Device Manager is used to identify the COM port automatically assigned to that adapter, which is required before any software configuration can proceed. With the hardware in place, a terminal emulator provides the software interface to the device. PuTTY is a widely used, free option available from its official download page, and selecting the correct installer version — typically 64-bit x86 for most Windows systems — ensures compatibility. Inside PuTTY, choosing the Serial connection type and entering the confirmed COM port number alongside a baud rate of 9600 establishes the session. Once connected, the device CLI appears and is fully available for show commands, enable mode access, and any subsequent configuration tasks.

What you'll learn

What's covered

Console Cable Connection Setup

Aligned to

Cisco CCST Networking
4.3 Identify the various ports on network devices
3.1 Identify cables and connectors commonly used in local area networks
5.5 Run basic show commands on a Cisco network device
Cisco CCNA
2.8 Describe network device management access

Key terms

Console
A physical port on a network device used for direct, out-of-band management access, typically via a rollover cable and terminal emulation software.
Rollover Cable
A cable wired so that the pins at one end are in the exact reverse order of the pins at the other end (pin 1 to pin 8, pin 2 to pin 7, and so on), used to connect a computer's serial port to the console port of a Cisco router or switch for out-of-band management. It is also called a Cisco console cable.
RS-232
A Layer 1 standard defining electrical signaling for serial communication between two devices over a point-to-point link.
COM Port
A serial communication port on a computer, identified by a number (e.g., COM3), used to establish a console connection to a network device.
Terminal Emulation
Software that simulates a terminal interface, allowing a computer to communicate with and configure network devices over a serial or network connection.
PuTTY
A free, open-source terminal emulation application used to establish serial, SSH, and Telnet connections to network devices.
Serial Connection
A direct, low-level connection type used in terminal emulation software to communicate with a device through a COM port at a specified baud rate.
Baud Rate
The number of signal changes per second on a communication channel, used to synchronize the speed of serial data transmission between devices.

Topics

Cisco Ios Console Access Putty Serial Communication Usb To Serial Device Manager Networking

Transcript

Console Cables

Now we're going to see how we can connect into these devices and start programming them.

I've got a couple of different cables here. Both of them have an RJ45 on the end here, but they're a flat cable, and the difference with this cable that you connect into Cisco equipment is that it is a rollover cable. All of the pins on a rollover cable roll over in the cable as it connects to the other device. This particular one actually just has an RS-232 on the end of it. The RS-232 is a common type of connector that was on a lot of computers; we don't see that as much anymore.

So what I'm actually going to do is use the USB connector. When you actually go to configure your terminal program, it can be a little more complicated when you're using USB, but we just don't see serial on computers as much as we used to, so it's becoming more and more rare.

It's pretty easy to connect into this. I just take my connector and I find the console, and then plug it right there into the console, and then I'm going to plug the other end into my computer.

Finding the COM Port

Now I've plugged the console cable into the device that I want to configure, and I plug the USB into the laptop that I'm going to be using. Here's the laptop. I'm on the laptop, and now what I'm going to do is get into the Device Manager. To do that, click the Start menu and type in Device Manager. That's going to pop up there, and we'll click on Device Manager.

We are going to find that cable that we plugged in under the ports, the COM and LPT ports. We open that up and we see USB Serial, and it is on COM3. So there, we now see that it's on COM3, and that's what we're going to use to configure this device.

Getting a Terminal Emulator

Next we're going to need some software that's going to interface with this equipment, so it's going to be some terminal emulator program that we're going to use. There are several different ones out there. There are a lot of free versions out there and there are a lot of paid-for versions out there. The one that I'm going to be demoing on throughout here is PuTTY, which is one of the free ones out there.

So I'm going to pull up a web page here and look for PuTTY. We're going to type in "putty download." Once again, if there are any advertisements that come up towards the top, I always bypass those. There are none here at this point in time, and I go for the top one that's displayed, and that's usually the legitimate link. So this one's "download putty," so I'm going to click on that one, and it says to download PuTTY I've got to click here, so I'll click here.

This is actually going to bring us to a different site, but this one is the safe site to download this on. So I take a look, and I am on a 64-bit and x86, so this is the one that I'm going to need. If you're on a Windows machine, there's a good chance you're on the 64 x86. So I'm going to download this software right here, and then I'm going to click it to install. I'm going to go through these steps to install this. I'm going to accept all of it, and I'm not going to view the readme file.

Connecting with PuTTY

Next we're going to get into PuTTY and connect to our equipment. I'm going to close out of this window right here and type PuTTY in there. For this case, I'm actually going to right-click this and pin this to the Start menu for easier access later. Actually, what I'll probably do is pin it to the taskbar as well, so now it's down here on the taskbar.

I can open it up, and now I have all these different connection types. I've got the different connection types that I can connect to all of these different pieces of equipment in different fashions, and we're going to be going over a couple of these. But for now we're just going to make a serial connection to this device.

To make a serial connection to this device, I'm going to click the serial that I'm going to connect to, and it's going to ask which serial line I'm going to connect to. I looked it up and it was serial line COM3, so I'm going to type in COM3 into there. Then I'm going to select the speed of 9600. So there, we're going to connect at a speed of 9600 to COM3. I'll click on Open, and then that's going to bring up the device.

First Contact with the Device

Now we can see that we're connected to this device, and one of the first things that comes up is a question: would you like to enter the initial configuration dialog? This is a wizard that will step you through the process of doing some initial configurations of this device. For now, we're going to jump straight into this device and just take a look around, so we're going to bypass this. I'm going to click no and hit enter.

Now I am on this switch and I can start programming it. I can start doing some show commands, I can get into the enable mode, I can do all of the commands to get this device programmed. So we are connected to this device, and that is how you do that.

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