Syed Jahanzaib Personal Blog to Share Knowledge !

April 11, 2018

Short Notes for Cisco 3850-24T IOS XE Upgrade & Stack Configuration

Filed under: Cisco Related — Tags: , — Syed Jahanzaib / Pinochio~:) @ 3:49 PM

ZAIB_ Cisco 3850- 24-t.jpg


1# Upgrade Firmware of Cisco 3850 24T-S (INSTALL MODE) by copying FW from TFTP to Switch Flash Directory

Read these first on BUNDLE vs INSTALL mode.

Last week we received new Cisco switches shipment having model WS-C3850-24T which will be replacing existing 3750 stack series in our data center. These switches have 2 methods of booting and running IOS XE software (in 3850).  By default, the switches comes with INSTALL mode. 

Before Upgrading Firmware ,we need to check for current mode in which the switch is currently booted in. [It should be INSTALL mode]

show version | begin Switch Port
Switch Ports Model SW Version SW Image Mode
------ ----- ----- ---------- ---------- ----
* 1 32 WS-C3850-24T 16.3.5b CAT3K_CAA-UNIVERSALK9 INSTALL
Configuration register is 0x102

We can use local USB as well to copy the firmware but since I already have TFTP for centralized backup for all Cisco switches therefore I am using TFTP method in this post.

Having TFTP server will give more leverage of doing various luxuries. copy the latest firmware to TFTP and then from switch console download the switch upgraded ISO and upload it to TFTP root folder. At the time of writing latest IOS XE version for 385024-T-S is cat3k_caa-universalk9.SPA.03.06.08.E.152-2.E8.bin

Connect to switch by ssh/telnet or by console and issue following command

copy tftp: flash:
Address or name of remote host []?
Source file name []? cat3k_caa-universalk9.SPA.03.06.08.E.152-2.E8.bin
Destination file name []? cat3k_caa-universalk9.SPA.03.06.08.E.152-2.E8.bin

After some minutes the new IOS will be downloaded to flash directory. in my case it took around 90 seconds to copy 291 MB IOS EX file.

# Switch to enable mode
#Issue command to upgrade to new firmware we just downloaded in above steps
request platform software package install switch all file flash:cat3k_caa-universalk9.SPA.03.06.08.E.152-2.E8.bin

Switch will now start the upgrade processing …

--- Starting install local lock acquisition on switch 1 ---
Finished install local lock acquisition on switch 1
Expanding image file: flash:cat3k_caa-universalk9.SPA.03.06.08.E.152-2.E8.bin
[1]: Expanding file
[1]: Finished expanding all-in-one software package in switch 1
SUCCESS: Finished expanding all-in-one software package.
[1]: Performing install
 SUCCESS: install Finished
[1]: install package(s) on switch 1
--- Starting list of software package changes ---
Old files list:
 Removed cat3k_caa-guestshell.16.03.05b.SPA.pkg
 Removed cat3k_caa-rpbase.16.03.05b.SPA.pkg
 Removed cat3k_caa-rpcore.16.03.05b.SPA.pkg
 Removed cat3k_caa-srdriver.16.03.05b.SPA.pkg
 Removed cat3k_caa-wcm.16.03.05b.SPA.pkg
 Removed cat3k_caa-webui.16.03.05b.SPA.pkg
New files list:
 Added cat3k_caa-base.SPA.03.06.08E.pkg
 Added cat3k_caa-drivers.SPA.03.06.08E.pkg
 Added cat3k_caa-infra.SPA.03.06.08E.pkg
 Added cat3k_caa-iosd-universalk9.SPA.152-2.E8.pkg
 Added cat3k_caa-platform.SPA.03.06.08E.pkg
 Added cat3k_caa-wcm.SPA.
Finished list of software package changes
SUCCESS: Software provisioned. New software will load on reboot.
[1]: Finished install successful on switch 1
Checking status of install on [1]
[1]: Finished install in switch 1
SUCCESS: Finished install: Success on [1]

Now issue reload command to restart/reload the new config.


Continue to reboot.

After the upgrade We will see new version in action !

show version | b SW
Switch Ports Model SW Version SW Image Mode
------ ----- ----- ---------- ---------- ----
* 1 32 WS-C3850-24T 03.06.08E cat3k_caa-universalk9 INSTALLConfiguration
register is 0x102

2# Short Notes on STACK Configuration!

cisco 3850 stack cable.jpg

Stacking is simple ! Example we want to connect 2 switches in stack mode.

1.  Power up the switch master only, let it boot completely,

2.   Attach the stacking cable from 1st switch to second one,

3.  Power up the second switch.

By default there will be no extra config required. and if both switches matches they will be added in STACK automatically.


1.  All switches are running the same IOS version, same Feature Set (example IP Base);

Setting Switch Priority for MASTER

We can set switch priority to decide which switch should be MASTER. To do this, Power ON the Master switch only and issue following command

sh switch

Switch/Stack Mac Address : 009a.d29c.daXX - Local Mac Address
Mac persistency wait time: Indefinite
H/W Current
Switch# Role Mac Address Priority Version State
*1 Active 009a.d29c.daXX 15 V07 Ready

Note down your switch number.

# switch to ENABLE mode
# Set Switch Priority
switch 1 priority 15
# RELOAD the configuration / reboot

now boot second switch.

Once all Done. Issue following command to confirm the STACKING status.

Switch#sh switch
Switch/Stack Mac Address : 009a.d29c.da00 - Local Mac Address
Mac persistency wait time: Indefinite
H/W Current
Switch# Role Mac Address Priority Version State
*1 Active 009a.d29c.da00 15 V07 Ready
2 Standby 682c.7b3c.4180 1 V07 Ready

Check Stack Ports status

Switch#show switch stack-ports
Switch# Port1 Port2

3# Some Useful STACK commands

show license right-to-use
switch stack-bandwidth
show switch detail

Following is one good Link for 3750 stack configuration …

4# Connecting Cisco 3850 Switch via USB console cable !

Following cable was used in this scenario

Console Cable 6 ft with USB Type A and mini-B

Console Cable 6 ft with USB Type A and mini-B

To connect with switch console using USB cable, first download & install the Cisco  USB Driver from my google drive

Now plugin the USB cable into your desktop/laptp, Open Putty and connect to switch with settings mentioned in the image, make sure to change port as per your local system setting

3850 putty setting

Syed Jahanzaib ~

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