If your 2900 router has a USB port:
Router# copy usbflash0:c2900-universalk9-mz.spa.157-3.m8.bin flash:
Do not rush to hit the "download" button. To ensure a successful upgrade, you must first verify your current setup.
Once you have the file, here is how to upgrade your router. Download C2900-universalk9-mz.spa.157-3.m8.bin -
Step 1: Verify Memory Requirements
Ensure your router has sufficient DRAM and Flash memory for the 15.7(3)M8 release. This version typically requires at least 512MB of DRAM and 256MB of Flash. Check via the command:
show version
Step 2: Backup Your Current Config
Always back up your running configuration before an upgrade.
copy running-config startup-config
(Ideally, also back up your current IOS to a TFTP server). If your 2900 router has a USB port:
Step 3: Transfer the File Connect your PC to the router via the Ethernet management port or a switch port. Use TFTP or USB to transfer the file.
Using USB:
Plug a FAT32 formatted USB drive into the router's USB port.
copy usb0:c2900-universalk9-mz.SPA.157-3.M8.bin flash:
(Confirm the filename matches exactly what is on your USB drive). Do not rush to hit the "download" button
Using TFTP:
copy tftp flash:
Enter the IP address of the TFTP server and the filename when prompted.
Step 4: Update the Boot Variable You must tell the router to boot from the new file.
Step 5: Reload
Reload the router to apply the changes.
reload
After the reboot, use show version to confirm you are now running 15.7(3)M8.