Cisco Catalyst 3650 Recovery from switch: Prompt Using USB
I first attempted recovery over TFTP.
Basic bootloader networking worked:
Code: Select all
mgmt_init
set IP_ADDR <switch-ip>/<subnet-mask>
ping <tftp-server>
and the switch could successfully reach the TFTP server.
I then tried:
Code: Select all
emergency-install tftp://<tftp-server>/cat3k_caa-universalk9.16.12.14.SPA.bin
The recovery environment started normally, but once it reached:
the management Ethernet link physically dropped.
The recovery environment then timed out while trying to download the IOS-XE bundle.
After confirming the bootloader network itself was working, I gave up on TFTP and used a FAT32 USB stick instead.
The IOS-XE image was copied to the USB root as:
Then from the bootloader:
Code: Select all
dir usbflash0:
emergency-install usbflash0:firmware.bin
This worked successfully. The switch validated, installed and verified the IOS-XE packages, then rebooted normally.
Final result:
Because the switch was now running in INSTALL mode, I also corrected the boot variable to:
Code: Select all
configure terminal
no boot system
boot system flash:packages.conf
end
write memory
Verification:
Flash should contain
and the extracted
files.
Main takeaway:
If TFTP works from the 3650 bootloader but the management link drops when the emergency recovery Linux kernel launches, USB
is a simple way around the problem.