Specifications

Chapter 1. Router Concepts 29
Router System and ConÞguration Files
The system software and configuration information for the router are contained in files in its DOS-compatible file
system. It is wise to keep a backup copy of these files. For more information on the backup and restoration of
configuration files, see page 162.
Any file contained within the system may be retrieved or replaced using the TFTP protocol. Specifically,
configuration files and the operating system upgrades can be updated. Only one copy of the router software is
allowed in the routerÕs FLASH memory. For more information on these topics, see Managing the Router, page
150.
Note: Users should not delete any of these files, unless advised to do so by Technical Support.
The router software files are as follows:
KERNEL.F2K Router system software (KERNEL.FP1 for IDSL routers).
ASIC.AIC FPGA (Field Programmable Gate Array) file that provides the logic that customizes the
router hardware.
The router configuration files are as follows:
SYSTEM.CNF These configuration files contain:
DOD Remote router database
SYS System settings: name, message, authentication method, and passwords
ETH Ethernet LAN configuration settings
DHCP.DAT DHCP files.
FILTER.DAT Bridge filters.
ETH.DEF File used by the manufacturer to set a default Ethernet configuration.
ATM.DAT ATM configuration file.
ATOM.DAT ATM configuration information.
SDSL.DAT SDSL configuration information.
DMT.DAT DMT configuration information.
IPSEC.DAT IPSec configuration information.
IKE.DAT IKE configuration information.
The following files are for automatic execution of command scripts. For more information, see page 166.
AUTOEXEC.BAT Autoexec file of commands to run on next reboot.
AUTOEXEC.OLD Autoexec file that has run already
The keys for software options that have been purchased are kept in the file KEYFILE.DAT. Do not copy the key
file from one router to another router, even if the two routers are the same model with the same kernel. The