Today I have experiencing  problem with Cisco-ASA that cannot boot to IOS  image. asa-1


We need to go to ROMmon mode by hit the Ctrl+Break during ASA boot up.


In ROMmon mode, erase all data in disk

rommon #1> erase all
About to erase the selected device, this will erase
all files including configuration, and images.
Continue with erase? y/n [n]: y
ata_cmd_response: drive not ready for command 0xec
ATA registers:
Drive/Head:0x0, Status:0x0, Error:0x0
Cylinder:0x0, Head:0x0, Sector:0x0
ata_soft_reset: Resetting CF card device @0x1f0, drive 0
ata_soft_reset: Resetting CF card device @0x1f0, drive 0 did not bring up the device 0
Disk0: is not present.
Erasing Disk1:

After erase data completely, configure ASA to boot image from tftp server to get into CLI for upgrade IOS normally.

My TFTP server IP Address is

*This is not about to upload IOS to ASA’s flash, It’s just boot from TFTP server. asa-3

When you get into CLI mode configure the management interface for upgrade IOS. Or you can go to Pre-configure Firewall then following the step to configure the management interface.

interface Management0/0
description Management Interface
 nameif management
security-level 100
ip address

Use copy tftp command to download IOS and ADSM from you TFTP server then reload ASA.

If you experiencing that ASA keep booting to rommon mode, You can do following to fix.

rommon #1> confreg
Do you wish to change this configuration? y/n [n]: y
enable boot to ROMMON prompt? y/n [n]: n
enable TFTP netboot? y/n [n]: n
enable Flash boot? y/n [n]: y
select specific Flash image index? y/n [n]: n
disable system configuration? y/n [n]: n
go to ROMMON prompt if netboot fails? y/n [n]: n
enable passing NVRAM file specs in auto-boot mode? y/n [n]: n
disable display of BREAK or ESC key prompt during auto-boot? y/n [n]: n