Remote Serial Console HOWTO

• Index
• Introduction
• What is a console?
• Why use a serial console?
• Alternative meanings of console
• Configuration overview
• Preparation
• Create fallback position
• Select a serial port
• Select a serial speed and parameters
• Configure the modem or the null-modem cable
• Configure the terminal or the terminal emulator
• Optionally configure the BIOS
• Configure the boot loader
• Configure the LILO boot loader
• Configure the GRUB boot loader
• Configure the SYSLINUX boot loader
• Configure Linux kernel
• Configure Linux kernel using LILO
• Configure Linux kernel using GRUB
• Configure Linux kernel using SYSLINUX
• Configure getty
• init system
• Traditional getty
• agetty
• mgetty
• mingetty
• No getty
• Configure incidentals
• Allow root to login from serial console
• Change init level to textual
• Remove saved console settings
• Serial console is not /dev/modem
• Alter target of /dev/systty
• Configure Pluggable Authentication Modules
• Configure Red Hat Linux
• Reboot and test
• Verify console operation
• Re-create saved console settings
• Test the console
• Where to next from here?
• Security
• Use good passwords
• Obey Data Terminal Ready and Data Carrier Detect
• Use or configure a dumb modem
• Restrict console messages
• Modem features to restrict usage
• BIOS features
• Use a boot loader password
• Non-interactive boot sequence
• Magic SysRq key
• Adjust behaviour of CtrlAltDelete
• Log attempted access
• Countering interception of telephony links
• Configuring a kernel to support serial console
• Linux kernel version 2.5
• Linux kernel version 2.4
• Linux kernel version 2.2
• Serial cabling
• Jargon
• Cable from console port to modem
• Cable from console port to terminal (or another PC)
• Lengths of serial cables
• Making serial cables
• Modem configuration
• Using Minicom to give commands to a modem
• Configure dumb modem
• Configure modem with AT commands
• Internal modems
• WinModems
• Bugs and annoyances
• Flow control in Linux kernel
• Red Hat Linux 7.1 and SysVinit
• BIOSs, keyboards and video cards
• Modem hangs up upon reboot
• init and syslog output does not display on secondary consoles
• The console is unresponsive after connecting
• Modem hangs up during initialization
• Boot loader has no flow control
• Boot loaders are vulnerable to line noise
• Advanced Power Management
• Modems and overseas telecommunications requirements
• Uploading files from a serial console
• Disable logging to console
• ASCII upload and cat
• Xmodem, Ymodem and Zmodem
• Kermit
• Upgrading Red Hat Linux from a serial console
• Select boot disk
• Configure the BIOS to use the serial port
• Configure modem to ignore DTR and assert DCD
• Prepare a network install floppy diskette
• Prepare HTTP server
• Record network configuration
• Record LILO configuration
• Upgrade Red Hat distribution
• Create boot disk for serial console
• Further references
• Upgrading Debian GNU/Linux from a serial console
• Terminal server configuration
• Considerations when buying second-hand terminal servers
• Cisco 2511
• Xyplex/iTouch MAXserver 1600
• Xylogics/Bay/Nortel Annex
• Livingston/Lucent Portmaster
• Gratuitous advice for developers
• Advice for boot loader authors
• Advice for BIOS authors
• About this HOWTO
• Copyright
• Disclaimer
• Acknowledgments
• Comments and corrections
• Colophon