be considered a 4-bit value, represented as a single hexadecimal digit. Cisco represents
hexadecimal values by preceding the hex digit(s) with 0x--for example, 0xA would mean a
single hex digit A.
in the configuration. Table 2-6 summarizes the use of the configuration register and the boot
system command at initialization time. (If the files referred to in the boot system commands are
not found, then the router will never complete the boot process. The password recovery process
must be used to change the config register to 0x2161 so that the NVRAM configuration is
ignored and the boot commands can be repaired to point to a valid IOS file name. Refer to the
section "Password Recovery," later in this chapter, for more details.)
Boot Field
determination mode, is entered.
fails, the router broadcasts looking for an IOS
on a TFTP server. If that fails, IOS from ROM
is loaded.
memory.
server.
any variety
first boot command in configuration. If that
fails, the second boot command is used, and
so on, until one is successful.