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New Member

Cat 6509 unexpectedly booted to slot0:

Durring an upgrade from 5.4(2) to 7.6(3a), one of our 6509's halted booting from bootlfash and switched to slot0, continued to boot from slot0. No lie, I perfomed this upgrade to twelve switches in a row without error, this was the first switch that gave me trouble.

I little more detail>> The bootflash statements were set to load the new os 7.6(3a) in bootflash first, then the old os 5.4(2) which I kept on the flash card in slot0 in case the bootlfash did'nt load.Good thing I did cause that's what happened. When I rebooted,(hard power down) the switch found the bootlfash image and begain decompressing 7.6(3a). After the image was decompressed, an error message popped up. The error mesage was from the AAA/Tacacs statements we removed from the config because the ACS server would be unavailable durring the reboot. Right after the error message popped up, the switch started to boot from slot0, which it did successfully, but to the old os on that card. Why did the switch not continue to load the bootflash 7.6(3a)??

My experience with mis-configured AAA/tacacs setting never caused much alarm, it just meant the switch defulted to local authentication, which it did anyway durring the upgrade. Those error messages are quite anoying, but you can still can your administration done.

Is there a key combination that can halt the image from loading? Did the AAA/TACACS error message inadvertantly tell the switch to boot from slot0?

That's the only hing I can come up with at this point.


  • Other Network Infrastructure Subjects
New Member

Re: Cat 6509 unexpectedly booted to slot0:

Is this a dual sup configuration? If so it can be tricky to move from one major revision to the other in a high availability setup. Due to the fact that the primary sup will force its running version of the os on to the secondary sup in certain situations.

If that's not the case make sure the version of the IOS is recommended for your version of the supervisory engine.

Just for reference, the following link has procedures for high availability upgrade procedures:

For recommended versions see

Good luck


New Member

Re: Cat 6509 unexpectedly booted to slot0:

Hi Lance,

Yes, this is a dual SUP setup. I did'nt enable HA until after we got the switch to load the new os. We did this by loading 7.6(3a) onto the pcmcia flash along with 5.4(2) and changed the boot parameter to boot: slot0: 7.6(3a), then bootflash:7.6(3a), then a third entry of 5.4(2) from slot0:. Rebooted and 7.6(3a) came up on slot0:. Since I wanted 7.6(3a) to come up on bootflash, I changed the boot statements again to first boot from bootlfash:7.6(3a), then slot0: 7.6(3a), then slot0: 5.4(2). Rebooted and this time it came up on bootflash:7.6(3a) no prob.

ONE THING I noticed while prepping the switches with the new OS and changing the boot statements, the "supervisor is sychronizong the NMP image.." message you get when you do this happened very quickly. Meaning, the "supervisor is sychronizong the NMP image" message and the "the supervisor has finished sychronizing the NMP image" message popped up on the screen at the same time, Where as the other switches I did, there was about a 3-4 minute delay before the "the supervisor has finished sychronizing the NMP image" message appeared. This leads me to beive the SUP's never synchronozed when I changed the boot statements on this switch? This switch and the other are running the same memory and flash storage.

Thanks for the response.

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