100-490 · Question #5
Which command initiates the transfer of a Cisco IOS image over IP from ROMMON?
The correct answer is D. tftpdnld. The tftpdnld command is specifically designed to initiate a TFTP (Trivial File Transfer Protocol) transfer of an image within ROMmon mode on a Cisco device. ROMmon Functionality: ROMmon (Read-Only Memory Monitor) is a basic operating system mode used when the main Cisco IOS is…
Question
Which command initiates the transfer of a Cisco IOS image over IP from ROMMON?
Options
- AXmodem
- Bcopy tftp: flash:
- Ccopy flash: tftp:
- Dtftpdnld
How the community answered
(29 responses)- A7% (2)
- B3% (1)
- C21% (6)
- D69% (20)
Explanation
The tftpdnld command is specifically designed to initiate a TFTP (Trivial File Transfer Protocol) transfer of an image within ROMmon mode on a Cisco device. ROMmon Functionality: ROMmon (Read-Only Memory Monitor) is a basic operating system mode used when the main Cisco IOS is unavailable. The tftpdnld command works from ROMmon to download a new IOS image. TFTP Protocol: The tftpdnld command utilizes TFTP, which is a simple and reliable protocol commonly used for transferring Cisco IOS images. Purpose: The command is used primarily for recovering corrupt images or upgrading to a different
Topics
Community Discussion
6
Mateus R.Oct 19, 2025Think of ROMMON as your router waking up with amnesia, no IOS loaded, no full operating system to speak of, just a bare-bones recovery shell like a PC booting into a rescue USB drive. In that stripped-down environment, the normal IOS exec commands like copy tftp: flash: simply do not exist yet, because the software that understands those commands never finished loading. The answer is D, tftpdnld, because that is the one command built right into ROMMON itself specifically for pulling an IOS image down from a TFTP server over the network. Xmodem is a valid recovery method too, but it works over the console cable, not over IP, so it does not fit what the question is asking about.
Imani T.Oct 20, 2025tftpdnld also needs you to manually set those ROMMON environment variables first, IP_ADDRESS, IP_SUBNET_MASK, DEFAULT_GATEWAY, TFTP_SERVER, and TFTP_FILE, or it just sits there doing nothing.
Grace U.Nov 19, 2025If you gravitated toward B, that instinct makes complete sense because copy tftp: flash: is exactly what you would reach for in a live IOS session, but ROMMON is a bare-bones environment that does not recognize that syntax, so the answer is D, tftpdnld, which is the command built specifically for pulling an IOS image down over IP from the ROMMON prompt.
Ingrid P.Nov 9, 2025tftpdnld is the ROMMON-specific command, not copy tftp: flash: which needs IOS running first.
Toby R.Oct 13, 2025I almost went with B because that copy command is burned into my brain from lab work, but then I remembered ROMMON is a stripped-down environment where the full IOS CLI is not available, so tftpdnld is the dedicated command that actually works there.
Imani T.Nov 6, 2025The wording "over IP" is doing a lot of work here and that's exactly why D is right and B is the trap. tftpdnld is the ROMMON command built specifically for pulling an IOS image down via TFTP when you have nothing else to boot from, and it only works because ROMMON has its own stripped-down IP stack that lets you set things like IP_ADDRESS and DEFAULT_GATEWAY as environment variables before you run it. Option B looks right if you've only ever recovered from a broken boot in a full IOS session, but copy tftp: flash: isn't a ROMMON command, it's a privileged EXEC command you'd run after you already have a working image loaded. Xmodem is the console cable method, no network required, so A is out the second you see "over IP." Lock in D and move on.