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Flash to new IOS

qbakies11
Level 1
Level 1

I'm trying to find instructions on how to upgrade my IOS version but all I'm finding are how to backup and restore config files. I use a TFTP server to backup my configs currently and I believe I can also use it to upgrade the IOS but I don't know how. Can someone point me in the right direction please?

1 Accepted Solution

Accepted Solutions

Quinton

If you connect to the console port and want to transfer the image over the console port it would need to use xmodem which is VERY slow.

If you have the image on a laptop, do you have tftp server software on that laptop? would it be possible to connect the laptop to a LAN port of the router (using a cross over cable) and transfer the image directly from the laptop to the router using tftp?

Another possibility to consider might be to use FTP instead of TFTP. If the server (or the laptop) where the image is has FTP server capability in addition to TFTP capability you would find that transferring the image with FTP is faster and more efficient than transferring with TFTP. I have had the experience several times where we were having problems getting a successful image copy using TFTP and it worked without a problem when we used FTP.

HTH

Rick

HTH

Rick

View solution in original post

11 Replies 11

Richard Burts
Hall of Fame
Hall of Fame

Quinton

There are several approaches (all similar) as to how to upgrade the IOS. You can use TFTP to copy a new image to the router, or you can use FTP to copy the image, or you can use protocols like SCP to copy the image. Since you mention TFTP I assume that is what you would prefer.

One caution about using TFTP: depending on the model of router and the feature set the size of the image will vary, but some of them get pretty large. There are some TFTP servers that have problems with images larger the 16 MB. So check on the size of the image that you want to upgrade to and check on your TFTP server to see if it will handle files as large as your image file. (or if it is difficult to check this - not very many servers have documentation that is explicit about this - then if you get an error using TFTP you will know that you may need to look for a different TFTP server.

The syntax might vary a bit depending on the model of the router you are upgrading but in general the command will be copy tftp: flash:

when you enter the command the router will prompt for information that it needs including the address of the TFTP server, the name of the image file on the server, and the name to use for the image in flash (usually the same as the name on the server).

HTH

Rick

HTH

Rick

ericgarnel
Level 7
Level 7

Are you talking about a switch or router?

The upgrade instructions are always included in the software release notes. due to platform specific issues, the following examples are really generic in nature

old example of router:

copy tftp://your-tftp-server-ip/the-new-image-bin flash:

you may have to set the system boot config if you leave the old image in flash

you may also have to delete the current image to make room in flash:

3560 & similar switch:

archive download-sw /overwrite tftp://your-tftp-server-ip/the-new-image-.tar

You can throw in a /reload if you want, I choose not to due to my superstitious nature

I have a 2610 and a 1720 that both need to be upgraded to a higher IOS version. I have already downloaded the new IOS files from the Cisco site using the IOS Upgrade Planner and the Feature discovery tool to make sure I got the right IOS versions that would do what I need and fit in the memory constraints of the routers.

I'm going to try the TFTP route and let you know if I have an issue. Thanks for the help thus far.

Quinton

Both the 1720 and the 2610 should take the copy tftp: flash: command to copy the upgraded IOS to the router. Depending on the amount of flash available you may be able to leave the old version of IOS is flash along with the new version or you may need to erase the old version to make room for the new version.

If the new version is the only IOS image in flash then a reload will cause the new image to load and run. If the old image is there along with the new image then you need to add a boot system flash: to the config and save the config to NVRAM before the reload.

HTH

Rick

HTH

Rick

Alright I tried to do the flash of the new image and ran into some issues. Before flashing to the new image I did a 'copy flash tftp' to copy the existing IOS version to my tftp server in case I needed to revert back to it. It copied to my tftp server successfully.

The router that I am trying this on is a 2610 so I downloaded c2600-i-mz.123-22.bin which fits in the memory constraints of my router. The tftp transfer took a very long time (a few hours) and in the end it didn't work. When I did a 'show flash' after the transfer finished I got the following:

c2600-i-mz.123-22.bin [deleted] [invalid checksum]

Then I decided to copy the original IOS back to the flash in case the router rebooted and it didn't have an IOS image to load. So I started the tftp transfer of the original IOS that I had copied over first and got the same message about invalid checksum. Why am I getting this?

I didn't find those terribly helpful but thanks for the links. I suppose it may be the traffic on the LAN (which is also why it would be so slow) but I don't know how else to try and do this.

If I were to connect a laptop to the console port and have the IOS file on that could I do the transfer while directly attached from the laptop?

Quinton

If you connect to the console port and want to transfer the image over the console port it would need to use xmodem which is VERY slow.

If you have the image on a laptop, do you have tftp server software on that laptop? would it be possible to connect the laptop to a LAN port of the router (using a cross over cable) and transfer the image directly from the laptop to the router using tftp?

Another possibility to consider might be to use FTP instead of TFTP. If the server (or the laptop) where the image is has FTP server capability in addition to TFTP capability you would find that transferring the image with FTP is faster and more efficient than transferring with TFTP. I have had the experience several times where we were having problems getting a successful image copy using TFTP and it worked without a problem when we used FTP.

HTH

Rick

HTH

Rick

Changing to FTP from TFTP mad a HUGE difference in speed (it took about a minute) and it was successful in the checksum. Thanks!

Quinton

I am glad that my suggestion was helpful in resolving your issue.

Thank you for using the rating system to indicate that your issue was resolved (and thanks for the rating). It makes the forum more useful when people can read about an issue and can know that they will read what successfully resolved the issue. I encourage you to continue your participation in the forum.

HTH

Rick

HTH

Rick

Are you running any Antivirus on the workstation ? If so, disable it during the file transfer. It may be corrupting the IOS image.

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