IP KVM Serial Console Switch

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Introduction to KVM over IP Serial Console

I recently setup a IP KVM Serial Console Switch which will allow get a Serial Console on some Linux Servers. There was a lot more involved in the setup than I originally thought.


Having a remote console is really useful, if not critical for remotely:

  • Dist-upgrading Servers
  • Rebooting Servers and Observing disk checks on reboot
  • Changing Bios Settings
  • Accessing Single User Mode and Booting from a Rescue CD
  • Access hung servers to see last console output (via kvm logs)
  • Fixing grub, boot and mdadm issues
  • Provide Remote assistance with onsite Admins


  • Not suitable for GUI/X interfaces
  • Old servers will not allow access to the bios via the serial console (limits advantages above such as booting from Rescue CD)
  • New Servers have to be set to output/redirect to the serial console (to see the bios etc.)
  • Grub needs to be configured specially to output to the serial console (AFAIK - even on new dell servers)
  • Requires a working network connection
  • Connecting via Serial Console may not show the previous console output (e.g.: if a server hung), however the KVM console may keep a separate console log you can use.

Setup of IP KVM Serial Console Switch

This particular KVM switch gets an IP Address (either manually set, or via dhcp). To setup the IP KVM Serial Console, you either need a DHCP network to attach to, or a serial console on a client computer to connect to the KVM switch to manually assign a static IP.

Setup static IP on the KVM Switch

We couldn't in-fact get the dhcp to work, and had to setup a serial connection to the KVM using minicom.

  • Plugin serial cable from client computer to the KVM
  • apt-get install minicom
  • minicom -s
           | Filenames and paths      |
           | File transfer protocols  |
           | Serial port setup        |
           | Modem and dialing        |
           | Screen and keyboard      |
           | Save setup as dfl        |
           | Save setup as..          |
           | Exit                     |
           | Exit from Minicom        |
#Choose Serial port setup. Choose ttyS0 for Serial Port 1. Choose E, 115200 8N1 and F, Hardware Flow Control Yes to match KVM Serial Console settings
   | A -    Serial Device      : /dev/ttS0                                 |
   | B - Lockfile Location     : /var/lock                                 |
   | C -   Callin Program      :                                           |
   | D -  Callout Program      :                                           |
   | E -    Bps/Par/Bits       : 115200 8N1                                |
   | F - Hardware Flow Control : Yes                                       |
   | G - Software Flow Control : No                                        |
   |                                                                       |
   |    Change which setting?                                              |
#After the above screen choose "Exit" on the main menu and this should connect via serial console.

Extra Options set in the KVM Switch

Once you have a static IP set from above, you can browse to the KVM Switch web gui on port 80, login as admin, admin and change the following settings.

  1. Serial Settings need to be changed for each of the 16 console ports. Make sure to set the Baud Rate to 115200
  2. Admin login needs to be changed. Default login is username: admin and password: admin
  3. Turn on console logging for each of the 16 console ports
  4. Change telnet to ssh for each of the 16 console ports
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