Quiz Entry - updated: 2026.07.30
What does the boot system command do on a Cisco switch, and what happens if the BOOT variable is not set?
Sets the BOOT environment variable that tells the switch which IOS image to load from flash; if it is not set, the switch just loads the first executable file it can find.
S1(config)# boot system flash:/c2960-lanbasek9-mz.150-2.SE/c2960-lanbasek9-mz.150-2.SE.bin
Command breakdown:
| Component | Meaning |
|---|---|
boot system |
The main command |
flash: |
The storage device |
c2960-lanbasek9-mz.150-2.SE/ |
Path to the file system (folder) |
c2960-lanbasek9-mz.150-2.SE.bin |
The IOS file name |
If BOOT variable is not set: The switch loads and executes the first executable file it can find in flash.
The startup-config file is called config.text and is stored in flash. Use show boot to verify the current IOS boot file.