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Configuring the DRAC 4 to Use a Serial or Telnet Text Console

Dell™ Remote Access Controller 4 Firmware Version 1.30 User's Guide

  Serial and Telnet Console Features

  Enabling and Configuring the Managed System to Use a Serial or Telnet Console

  Using the Secure Shell (SSH)

  Connecting to the Managed System Through the Local Serial Port or Telnet Management Station (Client System)

  Connecting the DB-9 Cable

  Configuring the Management Station Terminal Emulation Software

  Using a Serial or Telnet Console

The DRAC 4 provides serial and telnet command interfaces designed to perform all of the configuration and systems management functions using the DRAC 4 Web-based interface or racadm CLI.

The following section provides information about the serial/telnet text console features, and explains how to set up your system so you can perform systems management actions through a serial/telnet console.

Serial and Telnet Console Features

The DRAC 4 supports the following serial and telnet console redirection features:

• One serial client connection and up to four telnet client connections at one time
  
  
• Access to the managed system consoles through the system serial port and through the DRAC 4 NIC
  
  
• Serial/telnet console commands that allow you to power-on, power-off, power-cycle, reset, view logs, view sensor status, or configure the DRAC 4
  
  
• Serial/telnet console support for the racadm command, which is useful for scripting
  
  
• Command-line editing and history
  
  
• The connect com2 serial command to connect, view, and interact with the managed system text console that is being output through a serial port (including BIOS and the operating system)
  
  

NOTE: If you are running Red Hat Enterprise Linux on the managed system, the connect com2 serial command provides a true Red Hat Enterprise Linux console stream interface.

• Menu-based VT-100 block screen interface that provides easy operation of commonly used commands including reset, power-on, and power-off
  
  

NOTE: Because the racadm command does not have access to a file system on a serial or telnet console, several options (such as reading or writing a file) are not supported by the racadm command through a serial or telnet console. For more information about supported racadm commands for the serial and telnet consoles, see "Using the serial and racadm Commands."

• Optional idle timeout setting on SSH connections for enhanced security, controlled by the "cfgSsnMgtSshTelnetIdleTimeout (Read/Write)" object.
  
  

Enabling and Configuring the Managed System to Use a Serial or Telnet Console

The following subsections provide information about how to enable and configure a serial/telnet console on the managed system.

NOTE: The connect com2 serial command requires that the Serial Port setting under the BIOS setup group Integrated Devices be set to RAC. When a telnet session is established to the DRAC 4 and the setting of this serial port is not RAC, connect com2 yields a blank screen.

NOTE: The connect com2 serial command is not supported on systems running the Novell NetWare operating system.

Configuring the System Setup Program on the Managed System

Perform the following steps to configure your System Setup program to redirect output to a serial port.

NOTE: You must configure the System Setup Program in conjunction with the connect serial/telnet command.

1. Turn on or restart your system.
   
   
2. Press <F2> immediately after you see the following message:
   
   

<F2> = System Setup

3. Scroll down and select Integrated Devices by pressing <Enter>.
   
   
4. In the submenu, scroll down to Serial Port 1 and set to RAC.
   
   
5. Scroll down and select Console Redirection.
   
   
6. Set the Console Redirection screen to the following settings:
   
   

Console Redirection – Serial Port 1

Redirection After Boot – Disabled

7. Press <Esc> to exit the System Setup program to complete the System Setup program configuration.
   
   

Configuring Red Hat Enterprise Linux for Serial Redirection During Boot

NOTE: The following instructions are specific to the Red Hat Enterprise Linux GRand Unified Bootloader (GRUB). Similar changes would be necessary for using a different boot loader.

NOTE: In configuring the client VT100 emulation window, you must set the window or application that is displaying the redirected console to 25 rows x 80 columns to ensure proper text display; otherwise, some text screens may be garbled.

Edit the file /etc/grub.conf, as follows. See the sample file that follows, which shows the changes described in this procedure.

1. Add the following two new lines in the general settings section of the file:
   
   

serial --unit=0 --speed=57600
terminal --timeout=10 serial

2. Append two options to the kernel line:
   
   

kernel ............. console=ttyS0,57600

3. If the /etc/grub.conf contains a splashimage directive, you must comment it out.
   
   

Table 3-1. Sample File: /etc/grub.con

Additional information for editing the grub.conf:

1. You may need to disable GRUB's graphical interface and use the text-based interface instead; otherwise, the GRUB screen will not be displayed in RAC console redirection. To do so, comment out the line starting with splashimage.
   
   
2. If you have multiple options in GRUB and you want all of them to start a console session through the RAC serial connection, you need to add console=ttyS1,57600 to all options. The preceding example shows console=ttyS0,57600 added to only the first option.
   
   

Enabling Login to the Console After Boot

Edit the file /etc/inittab, as follows:

Add a new line to configure a getty on the COM1 serial port:

co:2345:respawn:/sbin/agetty -h -L 57600 ttyS0 vt100

See the sample file, which shows the addition of the new line.

Table 3-2. Sample File: /etc/innitab 

Edit the file /etc/securetty, as follows:

Add a new line, with the name of the serial tty for COM1:

ttyS0

See the sample file, which shows the addition of the new line.

Table 3-3. Sample File: /etc/securetty

Enabling the Serial/Telnet Console on the DRAC 4

You can enable the serial/telnet console locally or remotely.

Enabling the Serial/Telnet Console Locally

NOTE: You (the current user) must have Configure DRAC 4 permission in order to perform the steps in this section.

To enable the serial/telnet console from the managed system, type the following local racadm CLI commands from a command prompt.

NOTE: For detailed information about how to use the racadm CLI, serial/telnet, and racadm commands, see "Using the serial and racadm Commands."

racadm config -g cfgSerial -o cfgSerialConsoleEnable 1

racadm config -g cfgSerial -o cfgSerialTelnetEnable 1

Enabling the Serial/Telnet Console Remotely

To enable the serial/telnet console remotely, type the following remote racadm commands from a command prompt:

racadm -u <username> -p <password> -r <DRAC 4 IP address> config -g cfgSerial cfgSerialConsoleEnable 1

racadm -u <username> -p <password> -r <DRAC 4 IP address> config -g cfgSerial cfgSerialTelnetEnable 1

NOTE: Use the DRAC 4 IP address for your managed system; not 192.168.10.1 as shown in the example.

racadm -u root -p calvin -r 192.168.10.1 config -g cfgSerial -o cfgSerialConsoleEnable 1

racadm -u root -p calvin -r 192.168.10.1 config -g cfgSerial -o cfgSerialTelnetEnable 1

Using the racadm Command to Configure the Settings for the Serial and Telnet Console

This subsection provides steps to configure the default configuration settings for serial/telnet console redirection. To configure the settings, type the racadm config command with the appropriate group, object, and object value(s) for the setting that you want to configure. For a complete list of available serial/telnet and racadm CLI commands, see "Using the serial and racadm Commands."

You can type racadm commands locally or remotely. When using racadm commands remotely, you must include the user name, password, and managed system DRAC 4 IP address.

Using racadm Locally

To type racadm commands locally, type the commands from a command prompt on the managed system:

racadm config -g <group> -o <object> <value>

Using racadm Remotely

To use racadm commands remotely, type the commands from a command prompt on a management station with the following syntax:

racadm -u <username> -p <password> -r <DRAC 4 IP address> config -g <group> -o <object> <value>

Displaying Configuration Settings

To display the current settings for a particular group, type the following commands from the command prompt on the managed system:

racadm getconfig -g <group>

For example, to display a list of all of the settings for the cfgSerial group, type the following:

racadm getconfig -g cfgSerial

To display the current settings for a particular group remotely, type the following from a remote command prompt:

racadm -u <user> -p <password> -r <DRAC 4 IP address> getconfig -g cfgSerial

For example, to display a list of all of the settings for the cfgSerial group remotely, type the following from a management station:

racadm -u root -p calvin -r 192.168.0.1 getconfig -g cfgSerial

Configuring the Telnet Port Number

Type the following command to change the telnet port number on the DRAC 4.

racadm config -g cfgRacTuning -o cfgRacTuneTelnetPort <new port number>

Using the Secure Shell (SSH)

Secure Shell (SSH) is a command line session that has the same capabilities as a telnet session, but with higher security. The DRAC 4 supports SSH version 2 with password authentication. SSH is enabled on the DRAC 4 when you install or update your DRAC 4 firmware.

NOTE: SSH is not available for the first fifteen minutes of operation after installing/updating the DRAC 4 firmware. During this time the host keys are generated internally. No intervention is required for the host key generation. If this operation is interrupted for any reason, key generation will start over the next time the DRAC 4 starts up.

You can use either PuTTY or OpenSSH on the management station to connect to the managed system's DRAC 4.

NOTE: OpenSSH should be run from a VT100 or ANSI terminal emulator on Windows. Running OpenSSH at the Windows command prompt does not result in full functionality (that is, some keys do not respond and no graphics are displayed).

Only one SSH session is supported at any given time. The session timeout is controlled with the cfgSsnMgtSshTelnetIdelTimeout object as described in the "DRAC 4 Property Database Group and Object Definitions."

You can enable the SSH on the DRAC 4 with the command:

racadm config -g cfgSerial -o cfgSerialSshEnable 1

You can change the SSH port with the command:

racadm config -g cfgRacTuning -o cfgRacTuneSshPort 0x<port number>

For more information on cfgSerialSshEnable and cfgRacTuneSshPort objects, see "DRAC 4 Property Database Group and Object Definitions."

The DRAC 4 SSH implementation supports multiple cryptography schemes:

• Asymmetric Cryptography:
  
  
• Diffie-Hellman DSA/DSS 512-1024 (random) bits per NIST specification
  
  
• Symmetric Cryptography:
  
  
• AES256-CBC
  
  
• RIJNDAEL256-CBC
  
  
• AES192-CBC
  
  
• RIJNDAEL192-CBC
  
  
• AES128-CBC
  
  
• RIJNDAEL128-CBC
  
  
• BLOWFISH-128-CBC
  
  
• 3DES-192-CBC
  
  
• ARCFOUR-128
  
  
• Message Integrity:
  
  
• HMAC-SHA1-160
  
  
• HMAC-SHA1-96
  
  
• HMAC-MD5-128
  
  
• HMAC-MD5-96
  
  
• Authentication:
  
  
• Password
  
  
• SSHv2 (SSHv1 is not supported)
  
  

Connecting to the Managed System Through the Local Serial Port or Telnet Management Station (Client System)

The managed system provides access between the DRAC 4 and the serial port on your system to enable you to power on, power off, or reset the managed system, and access logs.

The serial console is available on the DRAC 4 through the managed system external serial connector. Only one serial client system (management station) may be active at any given time.

The telnet and SSH consoles are available on the DRAC 4 through the DRAC 4 NIC. Up to four telnet client systems and one SSH client may connect at any given time.

The management station connection to the managed system serial or telnet console requires the use of management station terminal emulation software (see "Configuring the Management Station Terminal Emulation Software" for more information).

The following subsections explain how to connect your management station to the managed system through a managed system external serial port using terminal software and a null modem cable, or by telnet using terminal software through the managed system DRAC 4 NIC.

Connecting the DB-9 Cable

If you want to connect to the managed system using a serial text console, you must connect a DB-9 null modem cable to the COM port that you are using on the managed system. Not all DB-9 cables carry the pinout/signals necessary for this connection. The DB-9 cable for this connection must conform to the specification shown in Table 3-4.

NOTE: You can also use this cable for BIOS text console redirection with the DRAC 4 serial console disabled.

Table 3-4. Required Pinout for DB-9 Null Modem Cable 

Configuring the Management Station Terminal Emulation Software

Your DRAC 4 supports a serial or telnet text console from a management station running one of the following types of terminal emulation software:

• Red Hat Enterprise Linux Minicom in an Xterm
  
  
• Hilgraeve's HyperTerminal Private Edition (version 6.3)
  
  
• Red Hat Enterprise Linux Telnet in an Xterm
  
  
• Microsoft Telnet
  
  

Perform the steps in the following subsections to configure your type of terminal software. Configuration is not required when using Microsoft Telnet.

Configuring Red Hat Enterprise Linux Minicom for Serial Console Emulation

Minicom is the serial port access utility for Red Hat Enterprise Linux. The following steps are valid for configuring Minicom version 1.8. Other Minicom versions may differ slightly but require the same basic settings. Use the information in "Required Minicom Settings for Serial Console Emulation" to configure other versions of Minicom.

Configuring Minicom Version 1.8 for Serial Console Emulation

NOTE: To ensure that the text displays properly, Dell recommends that you use an Xterm window to display the telnet console instead of the default window provided by the Red Hat Enterprise Linux installation.

1. To start a new Xterm session, type xterm & at the command prompt.
   
   
2. Drag the lower right-hand corner of the window to resize it to 80 x 25 prior to using Minicom. Drag the lower right corner with the mouse.
   
   
3. If you do not have a Minicom configuration file, go to the next step.
   
   

If you have a Minicom configuration file, type minicom <Minicom config file name> and skip to step 17.

4. At the Xterm command prompt, type minicom -s.
   
   
5. Select Serial Port Setup and press <Enter>.
   
   
6. Press <a> and select the appropriate serial device (for example, /dev/ttySo).
   
   
7. Press <e> and set the Bps/Par/Bits option to 115200 8N1.
   
   
8. Press <f> and set Hardware Flow Control to Yes and set Software Flow Control to No.
   
   
9. To exit the Serial Port Setup menu, press <Enter>.
   
   
10. Select Modem and Dialing and press <Enter>.
    
    
11. In the Modem Dialing and Parameter Setup menu, press <Backspace> to clear the init, reset, connect, and hangup settings so that they are blank.
    
    
12. To save each blank value, press <Enter>.
    
    
13. When all specified fields are clear, press <Enter> to exit the Modem Dialing and Parameter Setup menu.
    
    
14. Select Save setup as config_name and press <Enter>.
    
    
15. Select Exit From Minicom and press <Enter>.
    
    
16. At the command shell prompt, type minicom <Minicom config file name>.
    
    
17. To expand the Minicom window to 80 x 25, drag the corner of the window.
    
    
18. To exit Minicom, press <Ctrl+a>, <z>, <x>.
    
    

NOTE: If you are using Minicom for serial text console redirection to configure the managed system BIOS, it may be useful to turn on color in Minicom. To turn on color, at the command prompt type minicom -c on.

Ensure that the Minicom window displays a command prompt such as [DRAC 4\root]#. When the command prompt appears, your connection is successful and you are ready to connect to the managed system console using the connect serial command.

Required Minicom Settings for Serial Console Emulation

Use Table 3-5 to configure any version of Minicom.

Table 3-5. Minicom Settings for Serial Console Emulation 

Configuring HyperTerminal for Serial Console Redirection

HyperTerminal is the Microsoft Windows serial port access utility. To set the size of your console screen appropriately, use Hilgraeve's HyperTerminal Private Edition version 6.3.

To configure HyperTerminal for serial console redirection, perform the following steps:

1. Start the HyperTerminal program.
   
   
2. Type a name for the new connection and click OK.
   
   
3. Next to Connect using:, select the COM port on the management station (for example, COM2) to which you have connected the DB-9 null modem cable and click OK.
   
   
4. Configure the COM port settings as shown in Table 3-6.
   
   
5. Click OK.
   
   
6. Click File → Properties → and click the Settings tab.
   
   
7. Set the Telnet terminal ID: to ANSI.
   
   
8. Click Terminal Setup and set Screen Rows to 26.
   
   
9. Set Columns to 80 and click OK.
   
   

Table 3-6. Management Station COM Port Settings

The HyperTerminal window displays a command prompt such as [DRAC 4\root]#. When the command prompt appears, your connection is successful and you are ready to connect to the managed system console using the connect com2 serial command.

Configuring Red Hat Enterprise Linux XTerm for Telnet Console Redirection

NOTE: When you are using the connect com2 command through a telnet console to display the System Setup screens, set the terminal type to ANSI in System Setup and for the telnet session.

When running telnet with Red Hat Enterprise Linux, perform the following steps:

NOTE: To ensure that the text is properly displayed, Dell recommends that you use an Xterm window to display the telnet console instead of the default window provided by the Red Hat Enterprise Linux installation.

1. To start a new Xterm session, type xterm & at the command prompt.
   
   
2. Drag the lower right-hand corner of the window to resize it to 80 x 25 prior to using telnet. This can be done by dragging the lower-right-corner with the mouse.
   
   

Red Hat Enterprise Linux Xterm is now ready to connect by telnet to the managed system DRAC 4.

To connect to the DRAC 4, at the Xterm prompt, type telnet <DRAC 4 IP address>.

Enabling Microsoft Telnet for Telnet Console Redirection

NOTE: Some telnet clients on Microsoft operating systems may not display the BIOS setup screen correctly when BIOS console redirection is set for VT100 emulation. If this issue occurs, you can correct the display by changing BIOS console redirection to ANSI mode. From the BIOS setup menu, select Console Redirection → Remote Terminal Type → ANSI.

Microsoft telnet requires that you first enable Telnet in Windows Component Services.

After you have enabled telnet, you can connect to the DRAC 4 by performing the following steps:

1. Open a command prompt.
   
   
2. Type telnet <IP address>:<port number> and press <Enter> (where IP address is the IP address for the DRAC 4 and port number is the telnet port number if it has been changed).
   
   

Using a Serial or Telnet Console

NOTE: If you are a Windows XP or Windows 2003 user who is having problems with characters in a DRAC 4 telnet session, go to the support.microsoft.com website, and search the knowledge base for article 824810 for a hot fix for this issue. This problem may manifest itself as an apparently frozen login (the return key does not respond and the password prompt does not appear).

NOTE: With a Windows 2000 management station, pressing the <F2> key does not enter BIOS setup. This problem is resolved by using the telnet client supplied with the Windows Services for UNIX® 3.5 (recommended free download from Microsoft). You can download Windows Services for UNIX 3.5 from www.microsoft.com/windows/sfu/downloads/default.asp.

NOTE: When a telnet login attempt is invalid, a single session is counted toward the maximum of four sessions for approximately one minute after the invalid login attempt. If there are already three valid sessions, this invalid session will prevent further login attempts for that minute.

Serial and telnet commands, and racadm CLI can be typed in a serial or telnet console. These commands can be executed on the server locally or remotely. The local racadm CLI is installed for use as a root user only. For more information about the serial/telnet commands and racadm CLI, see "Using the serial and racadm Commands."

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