cat6k msfc2 boot procedure details?
Jochen Kaiser
Jochen.Kaiser at rrze.uni-erlangen.de
Fri Aug 15 09:47:00 UTC 2003
Good morning,
I try to understand the boot process of a msfc2 in cat6500 in
hybrid mode. After reading the appropriate docs at CCO and some
practise, I understand how to boot it and mostly (*sigh*) it
works.
Asking these detailed questions to ppl also administrating
cat6k revealed a deep lack of knowledge ;-(
Can anyone enlighten me/us?
---
I understand, that there are 4 mechanisms on the msfc2:
---------------------------------------------------------
1. config register
2. BOOT variable (???)
3. BOOTLDR for helper image
4. 'boot system' statement in nvram config
I assume, that there are 3 image types:
1. ROM image -> loaded when all fails
2. a c6msfc2-boot image -> loaded when other image fails
(that's what I've read, but I watched, that it is booted
each time, also when a loadable normal image is reachable
on bootflash)
3. a c6msfc2 -> regular image
Now we have different situations:
----------------------------------
a) an image is defined in nvram config 'boot system'
and the image is on the bootflash
-> image loads
b) an image is defined but not on bootflash
and there is an 'boot' image on bootflash
-> boot-image boots
my q:
- is the position of the boot image of any relevance?
I heard, that it is important, that it is the 1st
file on the bootflash. Is this right?
- does this just happen, when the config register has
the appropriate value of 0x2000 ?
- what is the exact role of the 'BOOTLDR'-variable?
c) no image defined, config register 0x102
and boot image is on bootflash
-> ????
my q:
- What happens?
d) an image is defined in the 'BOOT'-variable
-> ????
my q:
- what is the sense of the boot-variable?
- how is it set?
e) image is on ata-flash-disk and a boot image is on
bootflash. image is defined via nvram 'boot system'
-> since the appropriate image is not found,
it boots the 'boot' image from bootflash,
reads the nvram config and sees the sup-disk0 and loads
the real image as a replacement
my q:
- is this correct?
------------
Especially I've a problem with setting the boot-variable (during
normal operation of a regular booted image).
router#sh boot
BOOT variable = sup-disk0:c6msfc2-jo3sv-mz.121-19.E.bin,1
CONFIG_FILE variable does not exist
BOOTLDR variable does not exist
Configuration register is 0x2102
tia & greetings,
Jochen Kaiser
--
Dipl. Inf. Jochen Kaiser, GPG 0x3C93A870, phone +49 9131 85-28681
Network Administration mailto:jochen.kaiser at rrze.uni-erlangen.de
Regionales Rechenzentrum Universitaet Erlangen-Nuernberg, Germany
Homepage and PublicKey: http://ipv6.rrze.uni-erlangen.de/~unrz111
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