Scenario:
Make: Dell Networking
Model: Dell N4000 Series [N4032, N4032F, N4064, N4064F]
Mode: CLI [Command Line Interface]
Description: In this article, we will discuss a stepwise method of how to upgrade the firmware of a standalone Dell N4000 series switch using a TFTP server, including backup, activation, verification and rollback. If your switches are stacked, follow Dell N4000 Series Switch Stack Firmware Upgrade instead.
How Firmware Images Work on Dell N-Series Switches
Dell N-series switches store two firmware images in flash memory: an active image, which the switch is running, and a backup image. The safe way to upgrade is to copy the new firmware into the backup slot, mark it to load at the next reboot, and then reload. The old version stays in flash, so you can roll back quickly if anything goes wrong.
In this example, we upgrade an N4032F from version 6.3.3.14 to 6.5.4.12.
Before You Start
- Plan a maintenance window. A standalone switch must reload to load the new firmware, so all connected devices lose network access for several minutes.
- Download the correct firmware for your model from the Dell support website, and read its release notes. They tell you whether you can upgrade directly from your current version or need an intermediate version first, and whether a bootcode or CPLD update is required.
- Set up a TFTP server on a laptop or server connected to the switch network, and place the firmware file (.stk) in its root folder. On Windows, the free Tftpd64 works well.
- Use console access if possible. If something goes wrong during the reload, a console cable lets you see the boot process and recover the switch.
Upgrade Steps
Step 1: Check the Current Firmware Version
Log in to the switch and note the current active and backup versions:
edledge-switch#show version
...
unit active backup current-active next-active
----- ----------- ---------- --------------- -----------
1 6.3.3.14 6.2.7.2 6.3.3.14 6.3.3.14Step 2: Test Connectivity to the TFTP Server
Make sure the switch can reach the TFTP server. In this example, the TFTP server is 10.1.1.2:
edledge-switch#ping 10.1.1.2If the ping fails, check the IP addressing, VLAN and any firewall on the TFTP server. Windows Defender Firewall often blocks UDP port 69, which TFTP uses.
Step 3: Back Up the Running Configuration
Always save a copy of the current configuration before upgrading:
edledge-switch#copy running-config tftp://10.1.1.2/edledge-switch-backup.txt
Transfer Mode.................................. TFTP
Server IP Address.............................. 10.1.1.2
Destination Filename........................... edledge-switch-backup.txt
Data Type...................................... Config Script
Source Filename................................ running-config
Management access will be blocked for the duration of the transfer
Are you sure you want to start? (y/n) y
5245 bytes transferred
File transfer operation completed successfully.If you see an error during the transfer, refer to TFTP “Unspecified Error” During File Transfer.
Step 4: Make Sure You Can Still Log In After the Upgrade
Newer N-series firmware requires an enable password, or another authentication method such as RADIUS or TACACS+, before you can enter privileged mode over SSH or Telnet. If none is configured, set an enable password now and save, so you are not locked out after the reload:
edledge-switch#configure
edledge-switch(config)#enable password Str0ngEnablePass
edledge-switch(config)#exit
edledge-switch#copy running-config startup-configIf you are already locked out, see Reset Forgotten Dell Switch Password.
Step 5: Copy the New Firmware to the Backup Image
Transfer the firmware file from the TFTP server into the switch’s backup image slot:
edledge-switch#copy tftp://10.1.1.2/N4000v6.5.4.12.stk backup
Transfer Mode.................................. TFTP
Server IP Address.............................. 10.1.1.2
Source Filename................................ N4000v6.5.4.12.stk
Data Type...................................... Code
Destination Filename........................... backup
Management access will be blocked for the duration of the transfer
Are you sure you want to start? (y/n) y
TFTP Code transfer starting...
31954590 bytes transferred...
File contents are valid. Copying file to flash...
File transfer operation completed successfully.Important Note: Do not power off or reload the switch while the file is being written to flash. Wait for the message “File transfer operation completed successfully”.
Step 6: Confirm the New Image Is in the Backup Slot
edledge-switch#show version
...
unit active backup current-active next-active
----- ----------- ---------- --------------- -----------
1 6.3.3.14 6.5.4.12 6.3.3.14 6.3.3.14The new version 6.5.4.12 now appears under backup.
Step 7: Activate the New Image
Tell the switch to boot from the backup image at the next reload:
edledge-switch#boot system backup
Activating image backup ..Step 8: Confirm the Next Active Image
edledge-switch#show version
...
unit active backup current-active next-active
----- ----------- ---------- --------------- -----------
1 6.3.3.14 6.5.4.12 6.3.3.14 6.5.4.12next-active now shows 6.5.4.12, so the switch will load the new firmware on the next reboot.
Step 9: Save the Configuration and Reload
Save the configuration first, so nothing is lost, then reload the switch:
edledge-switch#copy running-config startup-config
edledge-switch#reload
Are you sure you want to reload the stack? (y/n) yThe reload usually takes a few minutes. If the release notes mention a CPLD or bootcode update, the switch may reboot more than once; do not interrupt it.
Step 10: Verify the Upgrade
After the switch comes back up, log in and check the version:
edledge-switch#show version
...
unit active backup current-active next-active
----- ----------- ---------- --------------- -----------
1 6.5.4.12 6.3.3.14 6.5.4.12 6.5.4.12The switch is now running 6.5.4.12, and the previous version 6.3.3.14 is kept as the backup. Finally, check that interfaces, VLANs, uplinks and connected devices are working normally.
How to Roll Back to the Previous Firmware
If you run into problems after the upgrade, you can switch back to the old version, which is still stored as the backup image:
edledge-switch#boot system backup
edledge-switch#copy running-config startup-config
edledge-switch#reloadAfter the reload, the switch runs the previous firmware again.
Troubleshooting
- TFTP transfer times out – check that the TFTP server is running, the file is in its root folder, and the firewall on the server allows UDP port 69.
- “File not found” – the filename is case-sensitive. Copy it exactly as shown in the TFTP server folder.
- Transfer fails with an invalid file error – make sure you downloaded the firmware for the N4000 series, not for another model such as the N2000 or N3000 series.
- Cannot enter enable mode after the upgrade – no enable password or authentication method was configured. Connect through the console or follow the password reset guide.
Frequently Asked Questions
How long does a Dell N4000 firmware upgrade take?
The file transfer usually takes a few minutes, and the reload takes another few minutes. Plan for about 15 to 30 minutes in total, including checks.
Can I upgrade a stack of Dell switches the same way?
The process is similar, but there are extra checks for stack members. Follow Dell N4000 Series Switch Stack Firmware Upgrade.
Do I lose my configuration when upgrading firmware?
No. The configuration is stored separately from the firmware. Still, always back it up first, as shown in Step 3.
Also, if you are looking to configure RADIUS authentication on the Dell switch, refer to Radius Configuration On Dell Switch, Radius Failover On Dell Switch, and Radius Failover Configuration On Cisco Switch for Cisco switches.
Disclaimer: This article is for educational purposes only and is not professional financial, medical, or legal advice. It may contain affiliate links, which earn us a small commission at no extra cost to you. See our Disclaimer and Affiliate Disclosure.
Article ID: EA00055