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How to upgrade the IOS of Cisco 2821 router

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How to upgrade the IOS of Cisco 2821 router

derflanoj
Hi to all TechRepublic people! I want to setup the VPN and firewall of our Cisco 2821 router, but when I tried to do it in SDM mode I received a prompt that I should upgrade the IOS of the cisco router. My problem are the ff:
1. I don't know how to upgrade the IOS because it is my first time to configure a Cisco using the SDM wizard.
2. Where can I can get the new IOS
3. What is the IOS new version that the cisco 2821
4. What should be done first before upgrading to the new IOS so that if my upgrade fail, I should be able to revert the previous IOS of the Cisco router.

Can anyone give me a step by step guide on doing this things especially my 4th question.
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    cisco

    1. I usually don't use SDM because it's not difficult to do it in CLI. because the IOS file for 2821 will be bigger than what tftp server can support, you'll need to setup an internal ftp server that you can reach from the 2821 router. Then, upload your existing IOS to the ftp server to test connectivity. If it was successful, erase your existing IOS. If you have enough space on your flash, you don't have to erase your existing IOS. Then, using copy ftp flash command, copy the new IOS to your flash directory. Then, using boot system:<new IOS image name>, you can choose to boot from the new IOS
    2. There are a few ways to acquire/purchase Cisco IOS. The proper way is to purchase Smartnet from Cisco and download the necessary IOS from the Cisco website.
    3. From Cisco?s website (software download), you can choose whichever version you want to download based on your preference. IOS that I?m running on our 2851 [2811, 2821, and 2851?s share same IOS] is (C2800NM-ADVIPSERVICSK9-M), Version 12.4(11)XW3 = c2800nm-advipservicesk9-mz.124-11.XW3.bin
    4. First thing would be saving your existing IOS to a ftp server. If you have enough space on your flash memory, simply leave the original IOS in the flash and using boot system: command, choose which IOS you?d like to use during system boot up.

  • +
    0 Votes
    cisco

    1. I usually don't use SDM because it's not difficult to do it in CLI. because the IOS file for 2821 will be bigger than what tftp server can support, you'll need to setup an internal ftp server that you can reach from the 2821 router. Then, upload your existing IOS to the ftp server to test connectivity. If it was successful, erase your existing IOS. If you have enough space on your flash, you don't have to erase your existing IOS. Then, using copy ftp flash command, copy the new IOS to your flash directory. Then, using boot system:<new IOS image name>, you can choose to boot from the new IOS
    2. There are a few ways to acquire/purchase Cisco IOS. The proper way is to purchase Smartnet from Cisco and download the necessary IOS from the Cisco website.
    3. From Cisco?s website (software download), you can choose whichever version you want to download based on your preference. IOS that I?m running on our 2851 [2811, 2821, and 2851?s share same IOS] is (C2800NM-ADVIPSERVICSK9-M), Version 12.4(11)XW3 = c2800nm-advipservicesk9-mz.124-11.XW3.bin
    4. First thing would be saving your existing IOS to a ftp server. If you have enough space on your flash memory, simply leave the original IOS in the flash and using boot system: command, choose which IOS you?d like to use during system boot up.