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New Member

Bad mask /24 for address 10.0.0.1

Hi,

I have a Cisco 2520 router with flash:igs-j-l.111-5. Why can' a 10.0.0.1 address be fiven a /24?

SanJose1(config-if)#ip address 10.0.0.1 255.255.255.0

Bad mask /24 for address 10.0.0.1

Thanks.

1 ACCEPTED SOLUTION

Accepted Solutions
Cisco Employee

Bad mask /24 for address 10.0.0.1

Hello,

You are running an extremely outdated IOS version. It probably defaults to classful routing behavior and avoids subnet addresses that overlap the address of the unsubnetted classful network (i.e. 10.0.0.0/24 and 10.0.0.0/8) - so-called subnet-zero addresses.

Try entering these two global configuration commands:

ip classless

ip subnet-zero

Then try configuring the 10.0.0.1/24 address on your interface again.

Best regards,

Peter

17 REPLIES
Cisco Employee

Bad mask /24 for address 10.0.0.1

Hello,

You are running an extremely outdated IOS version. It probably defaults to classful routing behavior and avoids subnet addresses that overlap the address of the unsubnetted classful network (i.e. 10.0.0.0/24 and 10.0.0.0/8) - so-called subnet-zero addresses.

Try entering these two global configuration commands:

ip classless

ip subnet-zero

Then try configuring the 10.0.0.1/24 address on your interface again.

Best regards,

Peter

New Member

Bad mask /24 for address 10.0.0.1

Thanks-The commands work.

Regards.

Said

New Member

Bad mask /24 for address 10.0.0.1

Could you assist with a 2610 router? I tried to update the image witout erasing the old image.  The router now goes in a loop while loading.  

rommon1 > dir

usage:dir

How can the router be made operational?

Thanks.

Said

New Member

Bad mask /24 for address 10.0.0.1

Could you assist with a 2610  router? I tried to update the image witout erasing the old image.  The  router now goes in a loop while loading.  

rommon1 > dir

usage:dir

How can the router be made operational?

Thanks.

Said

Cisco Employee

Bad mask /24 for address 10.0.0.1

Hi Said,

Can you post the transcript of the 2610 booting? There may be some information that will help us understand what went wrong.

Best regards,

Peter

New Member

Bad mask /24 for address 10.0.0.1

"..Configured I/O memory percentage was too large. Using 10 percent...."

Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-IK2S-M), Version 12.0(7)T,  RELEASE SOFTWARE (fc2)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Tue 07-Dec-99 07:48 by phanguye
Image text-base: 0x80008088, data-base: 0x80D78DB8


SYSTEM INIT: INSUFFICIENT MEMORY TO BOOT THE IMAGE!


System Bootstrap, Version 11.3(2)XA3, PLATFORM SPECIFIC RELEASE SOFTWARE (fc1)
Copyright (c) 1998 by cisco Systems, Inc.
TAC:Home:SW:IOS:Specials for info
C2600 platform with 24576 Kbytes of main memory


System Bootstrap, Version 11.3(2)XA3, PLATFORM SPECIFIC RELEASE SOFTWARE (fc1)
Copyright (c) 1998 by cisco Systems, Inc.
TAC:Home:SW:IOS:Specials for info
PC = 0xfff0a53c, Vector = 0x500, SP = 0x680127c8
PC = 0xfff0a53c, Vector = 0x500, SP = 0x680127b0

The following are the only options in rommon mode.

rommon 8 > dir ?

bad device name

rommon 6 > ?

alias               set and display aliases command

boot                boot up an external process

break               set/show/clear the breakpoint

confreg             configuration register utility

cont                continue executing a downloaded image

context             display the context of a loaded image

cookie              display contents of cookie PROM in hex

dev                 list the device table

dir                 list files in file system

dis                 display instruction stream

dnld                serial download a program module

frame               print out a selected stack frame

help                monitor builtin command help

history             monitor command history

meminfo             main memory information

repeat              repeat a monitor command

reset               system reset

set                 display the monitor variables

stack               produce a stack trace

sync                write monitor environment to NVRAM

sysret              print out info from last system return

tftpdnld            tftp image download

unalias             unset an alias

unset               unset a monitor variable

xmodem              x/ymodem image download

Thanks.

Said

Cisco Employee

Bad mask /24 for address 10.0.0.1

Hi Said,

You can actually look at the available devices name with the "device" command. Then do a dir with the proper device name and then boot :. Once the device is properly booted, configure the "boot system" command to point to the right :.

Regards

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
New Member

Bad mask /24 for address 10.0.0.1

Harold,

How do you find the device name?

Said

Cisco Employee

Bad mask /24 for address 10.0.0.1

Said,

You do not have enough DRAM to run that image. You have 24MB RAM while the image you are trying to boot needs at least 40MB RAM. If I understand you correctly, you currently have two IOS images in your FLASH.

If that is so, try using the dir flash: command to list the files in your FLASH. Then boot the other image using the boot flash:imagename command. Then, after the other IOS boots, delete the offending IOS from the FLASH. Do not use any or arrow keys when entering commands in the ROMMON mode in which you are located currently. If you make a mistake, erase it using the backspace key but otherwise, no line editing features are available, and if you hit a or an arrow key, the entire command line will not be accepted - you will have to write it again and of course avoid these keys.

Best regards,

Peter

New Member

Re: Bad mask /24 for address 10.0.0.1

Peter,

rommon 2 > dir flash:

         File size           Checksum   File name

   7891164 bytes (0x7868dc)   0xdfb0    c2600-ik2s-mz.120-7.t.bin

I have tried to download a smaller image from a tftp server numerous times. The image download from tftp server completes with the below  message.  The antivirus is turned off on the Win 7 box, I have changed  the cross over cable from the PC to the router, I have tried different  images to no avail.  The images tried were: c2600-io3-mz.122-23.bin, 5664KB and c2600-ik2s-mz.120-7.t.bin, 7,707KB.   Any suggestion?

"File reception completed.

TFTP copy: operation terminated due to bad checksum comparison.

rommon 23 > IP_ADDRESS=192.168.3.3

rommon 24 > IP_SUBNET_MASK=255.255.255.0

rommon 25 > DEFAULT_GATEWAY=192.168.3.1

rommon 26 > TFTP_SERVER=192.168.3.2

rommon 27 > TFTP_FILE=[smaller image] ?

rommon 28 > tftpdnld

The above resulted in a 'corrupt file

Kindly advise.

New Member

Bad mask /24 for address 10.0.0.1

rommon 1 > dir

Input redirection is not supported at this level

Output redirection is not supported at this level

New Member

Bad mask /24 for address 10.0.0.1

Harold,

rommon 2 > dev
Devices in device table:
        id  name
    flash:  flash

Kindly advise. 

Thanks.

Said

Cisco Employee

Bad mask /24 for address 10.0.0.1

Hi Said,

The next step would be to use dir flash: to look at the image names. It looks like you do not have enough memory to run the new image, so you will need to boot the old one instead.

Regards

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
Cisco Employee

Re: Bad mask /24 for address 10.0.0.1

Hi Said,

I wonder - what TFTP server are you using? Perhaps you could try to use a different TFTP server on your Windows machine. I have have good experiences using Tftpd32 or Tftpd64 (depends on your Windows version) downloadable here:

http://tftpd32.jounin.net/tftpd32_download.html

It would also be worth to verify whether the IOS image you are downloading from your TFTP server is not corrupted. However, neither of the images you have can fit into your DRAM. Images that appear to fit into 24MB of RAM are:

c2600-js-mz.120-28c.bin (ENTERPRISE PLUS)

c2600-i-mz.120-28c.bin (IP)

c2600-is-mz.120-28c.bin (IP PLUS)

c2600-d-mz.120-28c.bin (IP/IPX/AT/DEC)

c2600-ds-mz.120-28c.bin (IP/IPX/AT/DEC PLUS)

I would personally recommend going for any of the PLUS feature sets if possible.

Best regards,

Peter

New Member

Bad mask /24 for address 10.0.0.1

Peter,

I have been using Solarwinds tftp server.  Tftpd32 has been downloaded, however the router is not looking for the assigned directory from tftp32 for the image.  The router is looking for tftp-root folder.  I do not have access to the images you suggested.

Said

New Member

Re: Bad mask /24 for address 10.0.0.1

10.0.0.0.1
hello
New Member

Re: Bad mask /24 for address 10.0.0.1

You can try the Cisco device configuration settings for the 10.0.0.1 ip address. However, we recommend that you get advice from a network specialist.

hello
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