All posts by admin

How to update IOS (XE) on 3850

Step 1: Download and copy the latest IOS (XE) to the 3850 flash via USB or TFTP.

Step 2: Check the mode (Install or Bundle) of the switch by entering following command:

Switch#show version | begin Switch Ports

The out put will be as below:

Note: If the Switch is not in INSTALL Mode it’s highly recommended to switch INSTALL mode from BUNDLE mode. Click here to find out how or enter the below commands:

# software expand running to flash:
(config)#boot system flash:packages.conf

Step 3: Enter the following command to start installing the new IOS using the new code on the flash

Switch#:software install file flash:<New_IOS_File_Name>.bin
Switch#:software install file flash:cat3k_caa-universalk9.SPA.03.03.00.SE.150-1.EZ.bin
Then following will be shown:

Step 4: enter yes and hit enter.


NOTE: Ran into some issue booting 3850. This might be helpful if your Catalyst 3850 Fails to Boot.

3850-access#show boot
Switch 1
Current Boot Variables:
BOOT variable = flash:packages.conf;

Boot Variables on next reload:
BOOT variable = flash:packages.conf
Allow Dev Key = yes
Manual Boot = yes
Enable Break = no

Notice it’s set to Manual Boot = yes

you need to change that to NO

#conf t

(config)#no boot manual


If this also doesn’t fix the boot issue refer the following blog post here.

How to Password Reset on ASA 5505

Step1: Reboot ASA

Step 2: Wait till the you can see following “Use BREAK or ESC to interrupt boot.”  and then hit the ESC key, works on MAC/Terminal as well. (see below)


Step 3: Then you should land in “rommon #0>”

Step 4: Change the confreg valu to 0x41 as it tells to ignore its saved (startup) configuration upon boot

rommon #2> confreg 0×41

Step 5: reboot

rommon #2> reboot

Step 6: After the reboot you need to change the confreg value back to 0x01 and reboot.

ciscoasa(config)# config-register 0x01
ciscoasa# reboot

How to Password Reset on Catalyst 3850

Here are the quick easy steps to recover your 3850 switch password.

1. ​Power cycle the switch, press and hold the Mode button. Hold the mode button for approx. 15-30 sec, the Status LED will go amber. On the console make sure you are in Boot Loader mode.

Switch: flash_init
Switch: boot


2. After switch boots up.

Switch# copy startup-config running-config
Switch# configure terminal
Switch(config)# no system ignore startupconfig switch all
Switch(config)# exit
Switch# write

How to Password Reset on Nexus 5K

Here i will show how to step by step recover a password on N 5k (ex. N5548).

1. Do a hard reboot by unplugging the power cable.
2. Careful watch the switch boot up and when it gets to “Loading system software” (see below) and send break command “Ctrl + ]”.

Continue reading

How to recover a Cisco Switch from Boot Loader

Today I had to update a 3560x but when I consoled into the switch it was at Boot Loader prompt (switch:) and I wasn’t sure so I tried to boot and this is what happened.

switch: boot
Loading "flash:/c3560e-universalk9-mz.122-53.SE2/c3560e-universalk9-mz.122-53.SE2.bin"...flash:/c3560e-universalk9-mz.122-53.SE2/c3560e-universalk9-mz.122-53.SE2.bin: no such file or directory

Error loading "flash:/c3560e-universalk9-mz.122-53.SE2/c3560e-universalk9-mz.122-53.SE2.bin"

Interrupt within 5 seconds to abort boot process.
Boot process failed...

The system is unable to boot automatically.  The BOOT
environment variable needs to be set to a bootable

Continue reading