Cisco 4948, Star Wars, and IOS Upgrades

Fryguy — Tue, 13 Jul 2010 19:26:46 +0000

Just figured I would post a quick blurb on the Star Wars switch – The Cisco 4948. (Actually I think the whole 4500 series is Star Wars related).
Why do I say Star Wars Switch? Easy. Here are two SHOW VERSIONS from two Cisco 4948s that we have.
Cisco 4948 w/4 SFP
Cisco IOS Software, Catalyst 4500 L3 Switch Software (cat4500-ENTSERVICESK9-M), Version 12.2(31)SGA11, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Fri 08-Jan-10 16:44 by alnguyen
Image text-base: 0x10000000, data-base: 0x118C04CC
ROM: 12.2(31r)SGA1
Dagobah Revision 226, Swamp Revision 5
————————————————————————
Cisco 4948 w/10GE
Cisco IOS Software, Catalyst 4500 L3 Switch Software (cat4500-ENTSERVICESK9-M), Version 12.2(54)SG, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Sun 27-Jun-10 00:29 by prod_rel_team
Image text-base: 0x10000000, data-base: 0x123F21AC
ROM: 12.2(31r)SGA4
Pod Revision 0, Force Revision 31, Gill Revision 19
Dogabah? Swamp? Pod? Force?
I also have spoke with TAC engineers and they said that the CIsco 4500 team is into Star Wars like midi-chlorlians where to Ani.
So, now that I have that out of the way – my gripe on the Cisco 4948 out of the box.
When you receive one of these switches, the config-register is set to 0x2101 by default. Now, most people will not notice this until then want to upgrade the IOS code. What the 0x2101 on the 4948 does is tell the switch to load the first IOS image loaded into bootflash, not the one you configure in the boot variable. When you boot with 0x2101, here is the message that is flashed on the console:
_**\* The system will autoboot now ****
_
_config-register = 0x2101
Autobooting using the first file from bootflash…..
_
So, even if you load an newer IOS image in the system and configure the bootvar, the switch will not load that image. Below is a SHOW BOOTVAR showing the config-register of 0x2101 as well as the boot variable for the other IOS image in flash
4948-1#sh bootvar
BOOT variable = bootflash:cat4500-entservicesk9-mz.122-54.SG.bin,1;
CONFIG_FILE variable does not exist
BOOTLDR variable does not exist
Configuration register is 0x2101
4948-1#
So, when you change the config-register to 0x2102, the system will boot with the image file specified in the config.
_**\* The system will autoboot now ****
config-register = 0x2102
Autobooting using BOOT variable specified file…..
Current BOOT file is — bootflash:cat4500-entservicesk9-mz.122-54.SG.bin
_
Below is the bootvar after changing it as well as the config fil:
_4948-1#sh bootvar
BOOT variable = bootflash:cat4500-entservicesk9-mz.122-54.SG.bin,1;
CONFIG_FILE variable does not exist
BOOTLDR variable does not exist
Configuration register is 0x2102
_
While this is not really a big deal, it is enough to drive someone nuts in the middle of the night doing an upgrade. Just think, you uploaded code, checked the boot statement, but you IOS did not load. It is enough to drive a person crazy at times.
Just wanted to share…

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Cisco 4948, Star Wars, and IOS Upgrades