Wednesday, September 05, 2007

Configuring Minicom on Ubuntu to connect to Cisco Router

Ok, that was a large title for this task but what the heck. What needs to be done to achieve this? We need a piece of software called minicom (this has been around for ages, google it and you will learn a lot) and follow the next steps shown below:

a) install minicom and follow the normal procedures

sudo apt-get isntall minicom

b) check your serial ports.

We need to know the serial ports on your machine, so a dmseg would do the trick. Look for ttyS and take note of the number after it, in my case I have ttyS0 ready to use.

richard@wok:~$ dmesg|grep ttyS
[ 1.430818] serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[ 1.431528] 00:0c: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A

c) launch minicom as root

$sudo minicom

You will see a page as the one below. The first lines shows the configuration (I already modified mine, so yours must be the default ones).

c) Press control + a and Z to go to the menu. The first thing we will change is the dialing string so select the letter "O" for "command string" on the below menu.

d) The previous step should have brought you to the image below. With the arrows keys select "Modem and dialing" and press enter.

e) Now you are on the image below. Press A to set the cursor on the first line and delete everything (I use to have the following configuration ~^M~AT S7=45 S0=0 L1 V1 X4 &c1 E1 Q0^M ). One done press ESC or RETURN to go back to the menu.

f) Now back on the menu select "Serial Port Setup" with the arrow keys.

g) Using the letters configure the options:
A - For Serial Device
E - For Bps/Par/Bits

Copy the configuration below, the option "E" will bring a new menu where you select the details. The option A has to match with what you find on the dmseg step "b" of this guide.

h) Exit to the main menu and reset minicom. Restart it so the changes would take effect (maybe there is an option to make the changes live without restarting minicom but this is a small step).

After rebooting minicom with the Cisco router connected with the blue cable to your pc/laptop just turn the Cisco on and you will see the details on the screen and you are good to go. Example below:

I will add more details/tips along the way.

As always good luck!


macnet said...

Hi! I need this and your post was very helpful. thanks a lot! Greetings from Portugal

Michael said...

Excellent instructions. I got minicom set up and running within 10 minutes on by Ubuntu box. Thanks a million!

Anonymous said...


Good tutorial. I have configured my laptop LifeBook E Series on 10 minutes under Ubuntu Hardy 8.04.

I have tryed the connexion on a Cisco Catalyst 3560 Series PoE-8 without trouble.

Very nice !



kacole said...

great tutorial. only thing is to remember to turn off hardware flow control because it defaults to 'yes'. thanks again!

Anonymous said...

Awsome tutorial. Easy to understand and straight to the point.


Anonymous said...

I have two routers for my CCNA labs so worth saving the setup for serial port 0 as S0 and for port 1 as S1. Then next time start as " minicom S0" in one terminal window and as "minicom S1" in another terminal window.

Brockley Steve

Naresh said...

Hi, '
My return key(Enter) nor esc does not work with minicom when my device is connected to serial port, anyway flashes all that is going on in the device...How can I get rid of this..? Thanks in advance.

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J. Isaac D. T. said...

Grate tutorial
It worked for me...
Thank you

Isaac from Mexico