From: ccie2be (ccie2be@nyc.rr.com)
Date: Tue May 13 2003 - 09:15:05 GMT-3
Hi Sam,
Thanks for your response. I didn't know about these 2 flavors of 2500's. Is
there a way of telling which flavor a router is besides seeing if the copy
tftp flash command doesn't work? Maybe from the serial # or something in
the output of sh ver? Thanks very much. Jim
----- Original Message -----
From: "Sam Munzani" <sam@munzani.com>
To: "ccie2be" <ccie2be@nyc.rr.com>; "Group Study" <ccielab@groupstudy.com>;
"kym blair" <kymblair@hotmail.com>
Sent: Monday, May 12, 2003 10:34 AM
Subject: Re: IOS Upgrade problem
> In 2500 series there used to be 2 different kind of routers. 2500 and
> 2500-R. The second kind of routers had enough RAM to run whole IOS from
the
> RAM. It needed flash only during boot up and after that whole image was
> loaded in the RAM. These routers you can upgrade without config-register
> changes. All others required config register changes.
>
> Sam Munzani
> CCIE # 6479
>
>
> > Hey Kym,
> >
> > That has to be one of the best technical explanations I've ever seen.
> It's
> > certainly the only one on this topic that's ever made total sense.
Thank
> > you for taking the time to put in all the details. I'm sure many people
> > here on group study besides myself will greatly appreciate being able
to
> > understand this.
> >
> > There is one thing, however, that I still don't understand. At least
half
> a
> > dozen times I've upgraded the ios on 2500's without changing the
register.
> > I would do a copy tftp flash, then enter the source ip address, file
name,
> > etc. and the router would just copy the new ios into flash and then
> reboot.
> > When the router came back up it had the new ios. So, why does the
> register
> > sometimes have to be changed to upgrade the ios but not other times?
> >
> > This method worked on some routers even when the new ios was almost 16mb
> in
> > size and the old ios was erased first. Is there a way to know
beforehand
> > which method has to used?
> >
> > Thanks once again. Jim
> >
> > ----- Original Message -----
> > From: "kym blair" <kymblair@hotmail.com>
> > To: <ccie2be@nyc.rr.com>
> > Sent: Saturday, May 10, 2003 9:41 PM
> > Subject: Re: IOS Upgrade problem
> >
> >
> > > Jim,
> > >
> > > Most cisco routers copy the IOS into DRAM and run from DRAM, so flash
is
> > > READ-WRITE. 2500 routers execute from flash, so flash must be
> READ-ONLY.
> > > When you would like to erase and upgrade the image in flash, you need
to
> > > boot from BOOTFLASH (an older IOS version burned into BOOTFLASH chip).
> > >
> > > The config-register is a 16-bit register where each bit controls some
> boot
> > > option. For normal operation, boot to 0x2102 (i.e., 0010 0001 0000
> 0010;
> > > bit "15" is on the left; bit "1" is on the right).
> > >
> > > For maintenance, you may want to change the config-register and
reload.
> > >
> > > FIRST DIGIT: You will probably always want to keep the first digit set
> to
> > > "2" so bit 13 instructs the CPU to "boot from ROM if all else fails".
> > >
> > > SECOND DIGIT: You will probably also want to always keep the second
> digit
> > > set to "1" so bit 8 instructs the CPU to "disable [BREAK] after
bootup".
> > >
> > > THIRD DIGIT: you may want to change the third digit to "4" ... bit 6
set
> > to
> > > '0' says "copy startup-config into running-config during bootup",
where
> > bit
> > > 6 set to '1' says "don't use startup-config during the next bootup".
If
> > you
> > > set bit 6, you won't load the startup-config, but it will still be
there
> > in
> > > NVRAM. During operation, you could still "copy startup-config
> > > running-config".
> > >
> > > FOURTH DIGIT: Most importantly, you can instruct the router to boot
> > full-up
> > > using the image in flash (0x2102), or boot from older image in
bootflash
> > > (0x2101 or 0x2141), or boot into near-braindead ROMMON mode (0x2100).
> > Here
> > > are the various "show versions":
> > >
> > >
> > > ========== 0x2102 full boot from flash =================
> > >
> > > R3#sh version
> > > <snip>
> > > System image file is "flash:c2500-js-l.122-1.bin""
> > > <snip>
> > > 16384K bytes of processor board System flash (Read ONLY)
> > > <snip>
> > > Configuration register is 0x2102
> > >
> > > ========== 0x2101 boot from bootflash ===================
> > >
> > > R3(boot)#sh version
> > > <snip>
> > > System image file is "bootflash:"
> > > <snip>
> > > 16384K bytes of processor board System flash (Read/Write)
> > > <snip>
> > > Configuration register is 0x2101
> > >
> > > ========== 0x2100 boot into ROMMON mode =================
> > >
> > > >sh version
> > > ------ <nothing returned> -----
> > > >?
> > > $ Toggle cache state
> > > B [filename] [TFTP Server IP address | TFTP Server Name]
> > > Load and execute system image from ROM or from TFTP
server
> > > C [address] Continue execution [optional address]
> > > D /S M L V Deposit value V of size S into location L with modifier M
> > > E /S M L Examine location L with size S with modifier M
> > > G [address] Begin execution
> > > H Help for commands
> > > I Initialize
> > > K Stack trace
> > > L [filename] [TFTP Server IP address | TFTP Server Name]
> > > Load system image from ROM or from TFTP server, but do
not
> > > begin execution
> > > O Show configuration register option settings
> > > P Set the break point
> > > S Single step next instruction
> > > T function Test device (? for help)
> > >
> > > Deposit and Examine sizes may be B (byte), L (long) or S (short).
> > > Modifiers may be R (register) or S (byte swap).
> > > Register names are: D0-D7, A0-A6, SS, US, SR, and PC
> > > >
> > > >o
> > > Configuration register = 0x2100 at last boot
> > > Bit# Configuration register option settings:
> > > 15 Diagnostic mode disabled
> > > 14 IP broadcasts do not have network numbers
> > > 13 Boot default ROM software if network boot fails
> > > 12-11 Console speed is 9600 baud
> > > 10 IP broadcasts with ones
> > > 08 Break disabled
> > > 07 OEM disabled
> > > 06 Ignore configuration disabled
> > > 03-00 Boot to ROM monitor
> > > >
> > > >o/r 0x2102 <--- sets back to 0x2102
> > > >b
> > >
> > >
> > > One last item that is probably not useful on a 2500 router ... instead
> of
> > > setting the last digit to "2" for full-up operation, you could set the
> > last
> > > digit to "3", "4", ... "F". The "2" means to run the image in flash
> named
> > > "cisco2-2500" or the first image found. If you reconfigured to
"0x2103"
> > you
> > > would be instructing the router to run the image in flash named
> > > "cisco3-2500" or the first image found. This allows you to store
> several
> > > images in flash (memory permitting), and boot whichever you need
today.
> > >
> > > HTH, Kym
> > >
> > >
> > >
> > >
> > > >From: "ccie2be" <ccie2be@nyc.rr.com>
> > > >To: "Group Study" <ccielab@groupstudy.com>, "kym blair"
> > > ><kymblair@hotmail.com>
> > > >Subject: Re: IOS Upgrade problem
> > > >Date: Sat, 10 May 2003 20:10:05 -0400
> > > >
> > > >Hey Kym,
> > > >
> > > >Thank you so much. I don't understand why these register settings
> work,
> > > >but
> > > >so far, it's seems to be working fine. Right now the router is in
the
> > > >process of copying over the new ios.
> > > >
> > > >I looked up the register settings in Solie's Practical Studies and he
> > > >doesn't mention anything about bit 6 or bit 1 changing the flash from
> > read
> > > >only to read/write. Instead, he says setting bit 6 to 1 (4 decimal)
> > causes
> > > >the rtr to ignore nvram and bit 1 means to boot to boot mode. So, if
> you
> > > >could explain it, I'd like to understand why this works.
> > > >
> > > >But, in any case, this does work and I very much appreciate you help.
> > Jim
> > > >
> > > >----- Original Message -----
> > > >From: "kym blair" <kymblair@hotmail.com>
> > > >To: <ccie2be@nyc.rr.com>; <ccielab@groupstudy.com>
> > > >Sent: Saturday, May 10, 2003 6:50 PM
> > > >Subject: Re: IOS Upgrade problem
> > > >
> > > >
> > > > > Jim,
> > > > >
> > > > > Set your config register to 0x2141 and reload. After installing
> your
> > > >new
> > > > > IOS, change the config register back to 0x2102:
> > > > >
> > > > >
> > > > >
> > > > > R1(boot)#sh version
> > > > > <snip>
> > > > > 16384K bytes of processor board System flash (Read ONLY)
> > > > > Configuration register is 0x2102
> > > > >
> > > > >
> > > > > R1#conf t
> > > > > R1(config)#config-reg 0x2141
> > > > > R1(config)#end
> > > > > R1#reload
> > > > >
> > > > > System configuration has been modified. Save? [yes/no]: no
> > > > > Proceed with reload? [confirm]
> > > > >
> > > > >
> > > > > Router(boot)#sh version
> > > > > <snip>
> > > > > 16384K bytes of processor board System flash (Read/Write)
> > > > > Configuration register is 0x2141
> > > > >
> > > > >
> > > > >
> > > > > HTH, Kym
> > > > >
> > > > >
> > > > >
> > > > > >From: "ccie2be" <ccie2be@nyc.rr.com>
> > > > > >Reply-To: "ccie2be" <ccie2be@nyc.rr.com>
> > > > > >To: "Group Study" <ccielab@groupstudy.com>
> > > > > >Subject: IOS Upgrade problem
> > > > > >Date: Sat, 10 May 2003 16:01:11 -0400
> > > > > >
> > > > > >Hi group,
> > > > > >
> > > > > >I'm trying to upgrade from ios 12.0 to 12.1 on a 2501 with 16 mb
> > flash.
> > > > > >The
> > > > > >router to be upgraded also has version 11.0 bootstrap. The flash
> > isn't
> > > > > >partitioned and the version of ios I'm trying to copy is running
> fine
> > > >on
> > > > > >another 2501. I've tried copying the ios from both a PC running
> > > >Cisco's
> > > > > >TFTP
> > > > > >server s/w as well as another 2501 configured as a TFTP server.
It
> > > >doesn't
> > > > > >work in either case.
> > > > > >
> > > > > >I go through the tftp process but shortly after it starts, it
> fails.
> > (
> > > >I
> > > > > >can
> > > > > >ping the tftp server just fine.)
> > > > > >
> > > > > >I also noticed that with sho version, it says, 16384k bytes of
> > > >processor
> > > > > >board
> > > > > >system flash (read only)
> > > > > >
> > > > > >
> > > > > >On some of my other 2501's, it says, (read/write) instead of
(read
> > > >only).
> > > > > >Could this be the problem? And, how do I change the flash from
> (read
> > > >only)
> > > > > >to
> > > > > >(read/write)?
> > > > > >
> > > > > >Thanks in advance, Jim
> > > > >
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This archive was generated by hypermail 2.1.4 : Mon Jun 02 2003 - 15:13:41 GMT-3