How to Copy Cisco IOS to TFTP in Packet Tracer

With the Cisco Packet Tracer network simulation program, we can easily back up the IOS image to the TFTP server.

Copying Router IOS to TFTP in Packet Tracer

How to Copy & Backup Cisco Router IOS to TFTP Server

To copy the router images to the TFTP server, the Server must first be installed and configured in the network environment.

You can back up and restore the Router’s IOS to a TFTP server configured in a network environment. For example, If the IOS image fails in the event of a failure on the router, you can easily restore it from the server.

In fact, the only reason to back up is to be prepared for a potential disaster. If the iOS image is completely erased, the device will enter ROMmon mode. In practice, exiting this mode with the right commands is simpler than you think. The steps to recover your router from ROMmon mode can save you from this nightmare.

What File Format Should the IOS Image Be In?

Backing up and restoring Cisco IOS images is essential. First, make sure the image files are in the correct format. Typically, Cisco IOS image files have a “.bin” extension.

This format stands for binary. Following this, the router and other Cisco devices need this specific structure. Therefore, the binary file must be encoded correctly to work properly. Always verify the format before proceeding. This ensures smooth operations for your devices.

There are different types of files related to IOS, including “.tar” files. These files can hold one or more compressed images. They may also include related configuration files.

While you can use “.tar” files for installation, it’s best to use the standard binary file format (“.bin”) for backups. This format ensures compatibility and ease of use during restoration. By choosing “.bin”, you make the process simpler and more reliable.

To summarize, for adequate backups of Cisco IOS images, use the “.bin” format. This format makes it easier to copy and retrieve files.

Additionally, it helps maintain the IOS integrity during transfers. After transferring, always verify the file using a checksum. Using MD5 is a common choice. This step confirms that the file is not corrupted. Following these steps ensures a smooth backup and restoration process.

Backing Up Router IOS to the Server on Packet Tracer

Use the Packet Tracer to design a small network, and then follow the steps below to back up the IOS to TFTP.

To execute these commands, you first need to connect to the device via a console cable. To be clear, you cannot enter commands directly through the GUI. Direct access to the router via console connection is the starting point for all backup operations. If you skip this step, you will not be able to access the CLI interface.

Steps:

Step 1

First, open the Cisco Packet Tracer and create a network topology as follows.

Cisco Router and TFTP Server

Step 2

Click once on the Cisco Router R1, and in the window that opens, configure the GigabitEthernet0/0 interface according to the topology.

Router> en
Router# conf t
Router(config)# hostname R1
R1(config)# interface gigabitethernet 0/0
R1(config)# ip address 192.168.10.1 255.255.255.0
R1(config)# no shutdown
R1(config)# end

Assigning an IP Address to the Router's GigabitEthernet Interface

Step 3

Configure the TCP/IP settings of the FastEthernet interface of the TFTP server according to the IP block. Then click on the Services tab.

TFTP Server TCP/IP Settings

Step 4

To enable the TFTP service, select On and delete the files in it.

Deleting Files Backed Up to TFTP

Step 5

The TFTP server Root folder is now completely clean.

Files Backed Up to TFTP Deleted

Step 6

Test the network connection by pinging from R1 to TFTP with the Add Simple PDU on the right panel of the Packet Tracer software.

Ping with Add Simple PDU in Packet Tracer

Step 7

To back up the router image to the TFTP server, use the copy flash: tftp: command. Then, type the full name of the file you want to copy in the source filename (which file will be backed up) and press Enter.

As you can see in the image below, the IOS image has successfully been copied to the TFTP server.

R1# copy flash: tftp:

Using the copy flash:tftp: command

Step 8

When you check the TFTP server, you can see that R1’s IOS image has successfully transferred to the TFTP server.

Cisco Image Backup

Video

You can watch the video below to back up the router image file and also subscribe to our YouTube channel to support us!

Watch on YouTube

FAQ About Router IOS Backup and TFTP Operations

Why is backing up the IOS image so critical?

Think about a router. It is the heart of your whole network. If the operating system inside it, the IOS image, gets damaged, the device will not start. A simple power cut during a write process can harm the flash memory. In this case, instead of throwing the router away, you restore it from your backup. This is why backup saves lives.

Backup is a must, especially for devices in critical locations. Think of a production line in a factory. If the router stops, production stops. Every minute means cost. If you have a ready backup on the TFTP server, you finish the job in seconds.

Honestly, I have seen many device flash memories die in the field. System admins without backups end up helpless. The one with a backup sips a coffee and starts the restore. I think this difference says it all.

Which network settings should I watch when backing up to a TFTP server?

The first rule is IP reachability. The router and the TFTP server must be in the same network segment or in a routable setup. In Packet Tracer, give the server a static IP address. Set the router interface from the same block. Then ping it.

If you get no reply, the backup will not start. This is very basic but the most often skipped step. Make sure the interface is open with ‘no shutdown’. In the Services tab, TFTP must be in the ‘On’ position. Also, firewall software can block the TFTP port (UDP 69). This is not in the simulation, but keep it in mind for the real world.

Because TFTP connection works over UDP. It has low error tolerance. So there must be no packet loss on the network. Set up the VLAN correctly on the switch. If the router and server are on different VLANs, routing between them is a must.

What should I do if I see a .tar file instead of a .bin format?

On Cisco devices, the IOS image usually has a .bin extension. This binary file contains directly executable code. A .tar file is a compressed archive. A .bin file and sometimes web interface packs come out of it. It does not make sense to use a .tar for backup purposes.

First, you must open the .tar file and take out the real .bin image inside. Because when you restore with the ‘copy tftp: flash:’ command, the router expects the .bin format. If you load a .tar, the file system does not recognize it. In the end, the device cannot find the image at startup.

So when taking a backup, check the target file name. Copy whichever file name appears in the output of the ‘dir flash:’ command. If you do not write the name exactly the same, the job fails. In short, pay attention to uppercase-lowercase sensitivity.

When asked for ‘Source filename’ during backup, which name should I enter?

When you type ‘copy flash: tftp:’ on the router, it asks you for the source file name. Here you must write the full name of the active IOS image currently loaded on the flash memory. To learn the file name, first run the ‘show flash:’ or ‘dir flash:’ command. You will see the .bin file in the output.

For example, the file name could be a long text like ‘c2900-universalk9-mz.SPA.155-3.M4a.bin’. It is hard to type this without mistakes on the keyboard. I suggest you select it with the mouse and copy-paste with a right click. If you enter one wrong letter, the job will not start.

However, if you remember the file name wrong, do not panic. The ‘dir’ command is always your helper. Also, in Packet Tracer, some devices have only one .bin file in flash. Real devices may have more than one image. In that case, check which one is running with ‘show version’.

Why does the ‘copy tftp: flash:’ command give an error when restoring the image?

There are a few reasons for this error. The first is a broken IP connection. Repeat the test with ping. The second is that the file is not in the root folder of the TFTP server. Go to the server tab and make sure you see the .bin file in the list. The third is not enough space left on the flash memory. Check the free space with ‘dir flash:’.

If space is not enough, you must delete old or unneeded files. To do this, use the ‘delete flash:old_file.bin’ command. But be careful. You cannot delete the currently running IOS. The system warns you.

So the cleanest way is to free up space first and then start the restore. Also, pay maximum attention to uppercase-lowercase match when entering the file name. On real IOS devices, file systems are case-sensitive. So the name on the server and the name in the command must be exactly the same.

How do I verify that the backed up image is not damaged?

Do not celebrate just because the backup finished. Also do a check. The best known method is MD5 checksum comparison. On the router, you get a hash value with the ‘verify /md5 flash:image_name.bin’ command. Run the same command for the file on the TFTP server or calculate it with an MD5 tool.

If the two values are the same, the file is healthy. If they are different, there may have been packet loss during transfer. The file is damaged. Delete it right away and copy again. Skipping this step is like inviting disaster. If you write the damaged image to flash, the router will not start.

What is more, you will fall into ROMmon mode. Getting out of there is much harder. So make MD5 checking a routine. In big networks, scripts are even written to automate this job. Take my advice, do not count it done without checking.

Conclusion

In this article, I showed you how to copy the Cisco IOS image to the TFTP server using Packet Tracer. When you want to restore the backed-up IOS image from the server, you can use the copy tftp: flash: command!

Finally, it is very important to stress that learning to master the Packet Tracer screen like a pro from the start will speed up your work. So, you will not waste time with the toolbars in the right-hand panel.

How to Copy & Backup Cisco Router IOS to TFTP Server in Packet Tracer