How to boot 3850 in ROMMON mode

[AlekseyAndrosov]

Hi,

How do I boot 3850 Switch into ROMMON ?

Many thanks in advance.

[Peter Paluch · Accepted solution]

Aleksey,

This shouldn't be different from other similar Catalyst series: Connect to the console of the switch. Power off the switch, then press the MODE button and while keeping it pressed, plug the power back in. Keep the MODE button pressed and watch the console output. After holding the MODE button for roughly 10-15 seconds, the switch should end up in the switch: prompt - this is the "ROMMON" mode although these switches do not really have a ROMMON, rather, it is simply a bootloader prompt.

Check out this documentation as well:

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/3se/system_management/configuration_guide/b_sm_3se_3850_cg/b_sm_3se_3850_cg_chapter_01110.html#task_1021182

Best regards,
Peter

[Pablo_De_Azevedo]

Hi Peter,

Will the Mode button remove any configuration on the switch such assigned VLANs , interface switch mode, etc?

[uvega]

No, this process will not remove any device configuration