How to configure cisco router using linux for (COM port) configuration

Posted on in Categories Hardware, Howto, Linux last updated May 2, 2004

If you would like to configure Cisco router using Linux or FreeBSD (connected to a local COM port). Use the following instruction to configure device:

1) Connect cisco router to com port using serial cable

2) Use program like minicom (type minicom at a shell prompt)
$ minicom

3) Select the port, speed and /dev/ttyS0 as com1 port and save configuration as dfl. Next select Exit

4) Continue with your router configuration…

5) For more information on minicom read man page here

6) Other links:

* Cisco Router Configuration Tutorial
* Accessing a Cisco Router using FreeBSD (command also works with linux)

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

10 comment

  1. I realize this is an old post but I’ve made it my mission in life that whenever someone mentions minicom I’ll spread the good news of screen. Every admin should know GNU screen already (if not, go look it up) and it turns out that you can run ‘screen /dev/ttyS0’ and it takes care of setting up all of the speeds/etc. Plus you can disconnect and leave it running if you’re interested in catching log messages, etc.

  2. Hi everybody,

    My problem looks like this: after establishing the connection with minicom, cu, cutecom or gtkterm my laptop (IBM T42 in the dockstation II) sends every 8 seconds “AT” string and after about 4 seconds “^Z” string.

    In Exmp:

    Cisco#AT
    Translating “AT”
    % Unknown command or computer name, or unable to find computer address
    Cisco#^Z
    Cisco#
    Cisco#AT
    Translating “AT”
    % Unknown command or computer name, or unable to find computer address
    Cisco#^Z
    Cisco#
    Cisco#AT

    In that situation only cutecom allows me to work somehow (for example write an enable pass for privilaged mode). So the problem lies in configuration of the Ubuntu system 8.04 2.6.24-21.42-generic which I am using.
    I would be very glad for any suggestions.

    Thanks in advance,
    JWedrowycz

  3. OMG! Thank you. I have been looking for months for how to get terminal emulation from linux! This works perfectly for me.

    # speshak Says: December 1st, 2007 at 4:14 pm

    I realize this is an old post but I’ve made it my mission in life that whenever someone mentions minicom I’ll spread the good news of screen. Every admin should know GNU screen already (if not, go look it up) and it turns out that you can run ’screen /dev/ttyS0′ and it takes care of setting up all of the speeds/etc. Plus you can disconnect and leave it running if you’re interested in catching log messages, etc.

  4. Hi Sir,

    How r u.I am masum parvez from Bangladesh.I had learned linux server configuaration.Now I will want to learn how to configure a cisco router into a linux server.For this please you will help me?

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