Connecting Apple Laptop To Cisco Console Port

If you have physical access to a switch or router you can use a console cable to log into that router or switch. Doing so will allow you to make changes to the device’s configuration, such as setting the telnet password. Setting a telnet password will then allow you to log into the switch or router remotely. If you have an Apple laptop then the following is how you would connect to a Cisco device.

A console cable is what is needed to connecta laptop to a switch or router. This is sometimes called a rollover cable. It is usually flat and blue or gray and has a serial port on one end and a RJ45 on the other. The RJ45 end goes into the console port of the switch or router and the serial port goes into the device you are connecting to the switch or router.

Apple laptops however do not have a serial port. In fact, many laptops do not have a serial port. The answer is a USB to serial adapter. This will allow you to connect the console cable to your laptop as if your laptop did have a serial port.

Note that for many USB to serial adapters you will have to install the drivers. Drivers are the software which allow the adapter and your Apple laptop to work together. To do this you should go to the adapter manufacturer’s website and download the drivers.

If you do not know who the manufacturer is, you can connect the adapter to your laptop. Then click on About this Mac and then select the More Info… button. Look under the Hardware tab for USB. Here you should be able to select the adapter and see the vendor ID. This should give you the manufacturer’s name and you should be able to search the Internet and find a driver for the product. Another option is to use a Bluetooth to serial adapter. More about that later.

Once the driver is installed the USB adapter and the console cable should be ready to be used.

Once you have the laptop physically connected to the console port of the Cisco device what you want to do is open up a terminal session. Applications >Utilities > Terminal.

From here you must find out which USB port is connected to the device and then set the terminal to show the output from the USB port. You do this in the following manner:


macbook:user$ cd /dev
macbook:user$ ls -ltr /dev/usb
crw-rw-rw- 1 root wheel 9, 66 Apr 1 16:46 tty.usbmodem1a21


The ls -ltr lists the USB devices, in long format sorted by time, modified in reverse order. The last of the listed options should be the console cable, unless you plugged something else into another USB port since connecting the console cable.

Now you have the USB port which you want to connect to. In this example is it tty.usbmodem1a21. To connect you type:


macbook:user$ screen /dev/tty.usbmodem1a21 9600


At this point you should be connected to the device and can run all the regular Cisco commands such as enable etc. To disconnect from this console type Ctrl-a followed by Ctrl-\.

Bluetooth to Serial Adapter

Rather than dealing with a USB to serial adapter and all the driver issues that it might come with an alternative is to use a Bluetooth to serial adapter. This will allow you to connect to the Cisco switch or router via Bluetooth. Bluetooth does not need any new drivers installed on the Mac.

You should still be able to connect in the same manner as described above, only instead of


macbook:user$ ls -ltr /dev/usb


you will want to type


macbook:user$ ls -ltr /dev/tooth