Cisco 3845 Router has lost its configuration after reload on IOS upgrade

[Saleemjaffer]

Dear Friends,

I have a Cisco 3845 Router which was running with IOS ipbase 12.4(1a) version. Recently i have upgraded it to version 12.4-15 T9.

i followed the below steps to take effect the new IOS

1# New IOS is copied via a TFTP

2# Verified md5 and it was matched.

3# Changed boot statement from old to new IOS path.

4# Saved the config.

5# Reloaded the device.

After all the above steps are  success, the router came up with new IOS but it has lost its old configuration. Can anybody guide me what made the device wrong to lose its configuration.

[paolo bevilacqua]

Hard to know.

For good practice, always save configurations somewhere outside the router.

[milan.kulik]

Hi,

is the startup config still available in the NVRAM?

Does sh start or dir nvram:

show anything?

HTH,

Milan

[Saleemjaffer]

i didnot noticed the sh startup and dir nvram on or after reload. but now i have reconfigured everything from my manual backup. But i would like to know the cause of this problem.

is there any parameters that would erase or lose the device configs.

[Leo Laohoo]

Maybe the configuration registry is incorrect?

Sent from Cisco Technical Support iPhone App

[milan.kulik]

Hi,

as Leo noticed, confreg settings might cause startup config being ignored, e.g.

(That's usually used for password recovery.)

That's why I asked if the startup config was still in the NVRAM.

Sometimes the IOS  notices the config was created by another IOS version as is prompting to confirm to use it - but usually while being saved, if I remember correctly.

BR,

Milan

[glen.grant]

  Check the config register and make sure it not set to ignore the startup config . Register should normally be  0x2101 or x2102 .  if its something other than that it may be ignoring the startup config.