Bootloader Question

[Patrick McHenry]

I've been upgrading our switches to support ssh and have been doing so without any problems. While looking at the sh ver output to see the image that was on a switch I saw the Boot Loader output. I've seen it before but, never gave it much thought. Is the Boot Loader something that should be upgraded as well when the image is upgraded or is this something that should stay the same for the life of the switch?

Could I run into problems when upgrading a switch without upgrading the boot loader?

System image file is "flash:c2970-i6l2-mz.121.14-EA1a/c2970-i6l2-mz.121.14-EA1a.bin"

C2970 Boot Loader (C2970-HBOOT-M) Version 12.1(14)EA1, RELEASE SOFTWARE (fc1)

Thanks, Pat.

[hobbe · Accepted solution]

If I am not mistaken it does get upgraded when you upgrade the IOS in the switch.

if I am not mistaken, not all IOS contains new bootloader and / or microcode.

I think you can find the information in the release notes.

Good luck

HTH

[Patrick McHenry]

Thanks Hobbe

[Leo Laohoo · Accepted solution]

If you have switches that will support 12.2(50) and later, the IOS will upgrade the bootloader/bootstrap.

[Patrick McHenry]

And if the present image is older you must install a bootloader? Or, it could need one or it could not depending on the switch model? Now that I think about it I haven't seen the bootloader software on the cisco site. Have you?

[Leo Laohoo]

And if the present image is older you must install a bootloader?

Not unless you want to.  For example, when the 12.2(50)SE IOS came, I found out that the bootloader gets upgraded (that's fine).  But then bugs in this software made me downgrade to 12.2(46)SE.  Now if you upgrade to the 12.2(50)SE IOS for the first time, the switch will upgrade the bootloader, REBOOT, and load the new IOS.  This takes time.  If you are doing this remotely, your heart could stop (mine did).  So what I did to newly arrived switches was to upgrade the IOS to 12.2(50)SE, which upgraded the bootloader, and downgrade to 12.2(46)SE.  I know it's a big task but I decided that sometimes remotely upgrading IOS can go wrong so I'd rather do it now than later.

Or, it could need one or it could not depending on the switch model?

IF your switch will support 12.2(50)SE then it will upgrade the bootloader.  For example, 2970 won't support 12.2(50)SE so the bootloader will remain the same.

Now that I think about it I haven't seen the bootloader software on the cisco site. Have you?

For access switches, no.  There are bootloader/ROMmon upgrades available to the Sup32/Sup720 and ISR G1 routers.