2950 - Power cycle issue

[Jeff Harned]

Hi All,

I am new to networking but have been working with a small LAN setup with success.

This is my issue:

I am using one 2950 switch along with data converison devices converting incoming serial data to multicast data back to serial data.
For the switch configuration I have chosen to use MVR (Multicast VLAN Registration) assigning ports in a VLAN (Virtual LAN) configuration.

I save the configuration steps using the "copy running-config startup-congfig" command.  So far everthing is working great!

However, when I do a power cycle on the switch the ports become inactive (although the port status LEDs are green).  I know no multicast data is getting through to the devices because there are no data activity LEDs lit up on them.

Performing a "show running-config' on the switch shows that the configuration entries are intact.  To get the LAN setup to work again I have to retype the configuration steps again into the switch.  Can someone help me with this issue?

Thanks.

Regards,

Jeff

Cisco 2950 Switch
IOS Version 12.1(22)EA9
Running Standard Image

24 FastEthernet Ports

[ebarticel]

Hi Jeff,

I dont't understand how you could ssh to the switch when your vty lines are not configured.

I have a 2950 switch in my lab. I will load in your config and see what is wrong.

Eugen

PS. Check the attached file and if you need help with ssh let me know

[Peter Paluch]

Jeff and Eugen,

The RSA keys are invalidated if the device's hostname or domain name changes. This could have easily happened: after renaming the config.text to a different filename, the switch booted using the default empty configuration, resulting in change of the hostname to the default of 'Switch' and removal of the domain name. The RSA keypairs may have been invalidated as a result, and thus, the SSH does not work anymore.

Would this explain what you saw here?

Best regards,

Peter

[ebarticel]

Hi Peter,

I had a look at the output of "show run" command that Jeff posted before the changes to config.text file and I don't see any configuration on the vty lines for ssh access.

Initial problem was than when rebooting the switch the configuration will default to a configuration and Jeff had to manually reconfigure the missing commands. Based on that description I assumed that the switch is configured to boot a certain config file, while Jeff was saving to other file. Unfortunately I can't test ssh config as my 2950 does not support ssh, only telnet.

Regards

Eugen

[Jeff Harned]

Hi Peter,

I must of done this using the copy command.  I replied back to Eugen and will continue on with these issues.

Thanks.

Regards,

Jeff

[Jeff Harned]

Hi Eugen,

First, thanks for all your help!! 

I will l have to look up info on vty.  As far as accessing the switch, I created the neccassary keys and up to this point was able to access the switch using ssh.  I am not using a Windows environment, I simply access the switch through the CLI and once inside the switch I add the configurfation files.  I will look closely at your document and appears I will have to clear the nvram as you stated and start over.  Hopefully this will allow me to access the switch again using ssh and solve this power cycle issue!!

I will  let you know.

Thanks.

Regards,

Jeff

[Jeff Harned]

Hi Eugen,

Not looking good.  After further testing this is the summary of where I am at now.

This is what I have done:

I deleted the flash:vlan.dat

Erased nvram

I loaded up my configuration again and the system generated a configuration file named config2.txt?  Inside this file is the configuration steps that I entered.  So I figure this is the file that the system is looking for to load?

When I cylce power to the switch I once again get no data to my destination unit. I also now have no access to the switch using ssh like I did before!!.  What I did through the console port was to enter the following command:  "copy flash:config2.txt system:running-config".  What this did is pass the multicast data to the destination units but lost ssh!!

After I do another power cycle I once again have no data.  Running the above command again once again causes the data to output to the destination units.

So through all this I now lost ssh on power cycle.

Enclosed are the flash and boot files.

Thanks.

Regards,

Jeff

[ebarticel]

Hi Jeff,

Can I ask if when you use copy running-config startup-config, do you type a name for the file? or just accept the default value by pressing the Enter key?

If you don't accept the default value then the switch doesn't know where to look if other variables are not set as well.

Please check the nvram as well.

Use this command to move to nvram "cd nvram:" then use "dir" to view contents of nvram and post the output.

I see in your flash boot output that BOOT path-list is empty. Try this command in global config:

Switch(config)# boot system flash:/c2950-i6k2l2q4-mz.121-22.EA10.BIN

The ssh configuration can be done like this:

Change the name and values to suit your neeeds

Switch(config)#ip domain-name yourdomain.com

Switch(config)#username Jeff privilege 15 password 0 cisco

Switch(config)#line vty 0 4

Switch(config-line)#privilege level 15

Switch(config-line)#login local

Switch(config-line)#transport input ssh

Switch(config-line)#exit

Switch(config)#line vty 5 15

Switch(config-line)#priviledge level 15

Switch(config-line)#transport input ssh

Switch(config-line)#login local

Switch(config-line)#exit

Switch(config)#crypto key generate rsa

How many bits in modulus[512] 768

When the key generation is finished, save your configuration.

You can test from a pc with "ssh -l Jeff cisco" or a putty program.

Eugen

[Jeff Harned]

Hi Eugen,

Thanks for the info.

Not much success, however I was able to copy the boot flash file into the path-list.  As far as where I copy the running-config startup-config file is in the defult destination file "startup-config".  I had trouble with configuring the ssh, so I tried it another way.  I was able to capture some files for you to view before and after I power cycle the switch.

In the after power cycle docoument I noticed that the startup-config file is empty under the nvram directory?  Maybe this is a clue??

Couple of notes: Before the power cycle I was able to access the switch using ssh and the data was going to the desination units.  After the power cycle no data getting through and unable to access the switch using ssh.

Thanks.

Regards,

Jeff

[ebarticel]

Hi Jeff,

I had a look at your file and I saw something interesting

The boot paths have flash:/filename.

The paths should be flash:filename  -without forward slash "/"

Try boot switch in ROMmon mode and issue

switch: reset

Then check the paths again with "sh boot", if didn't change you may have to manually set them but don't use the "/", just flash:filename

If all this does not work I am affraid that you may need to delete and copy the IOS again using xmodem.

Let me know how it is going

Eugen

[Jeff Harned]

Hi Eugen,

I have no experience using the ROMmon feature but looked it up and made an attempt to try it with no success.

However, I was able to copy the BOOT path-list without the "/". 

1) Under the BOOT path-list: Config file:

I do not understand where the config2.txt is coming from but it appears to get created after doing a "copy running -config startup-config" command after I do a reload.  When I do a "copy running-config startup-config" command it appears this is what is loaded into the startup-config file after viewing the same number of bytes as shown in the attachment: '"1929".

Should this file be stated as: "flash:config.text" instead of config2.txt?

I know you are going to ask, what do I mean by a reload?  To renter my configutartion steps again this is what I have done:
After holding the mode switch until all the LEDS turn solid I go to switch >enable

delete flash:vlan.dat

erase startup-config

reload

Enter the initial configuration dialog then follow all the prompts   After the last one that states save this configuration to nvram, I select 2 to save it.

I then log into the switch and add the configuration files.

2) As you can see from the attachment that under the dir nvram: I loose the startup-config file, it empties out after a power cycle.

Thanks.

Regards,

Jeff

[Jeff Harned]

Hi Eugen,

Some questions:

After a power cycle as I stated before, when I look under the "dir nvram:" the startup-config file states 0 bytes.

Why, when I opened up this file it has the configuration files intact yet nothing is working and it states 0?

Where is the "running-config" file, I see no files listed as such.  Is this file being copied to and named this "config2.txt" file that I keep seeing?

Thanks.

Regards,

Jeff

[ebarticel]

The startup-config file works with config.text by default. In your sh boot output the path to config file is not flash:config.text anymore, it has been chaged to config2.txt. The startup-config in nvram doesn't know where that config2.txt is, because in the path startup-config looks at config.text, and since the path to that file has chnaged, the value will be zero. Also every time you erase nvram that file is 0.

The running-config file reside in RAM, and all the configurations are lost when you reboot the switch, if you don't save them, same as a document on your computer.

You may have to remove that config2.txt and change the path back to config.text

"boot config-file flash:config.text"

Also on your boot output when you save the file it says "Configured from console by rici on consolecopy". I never saw consolecopy, just console or vty. What is consolecopy?

Eugen

[ebarticel]

Why you select 2 when saving to file?

At this prompt "Destination filename [startup-config]? "

you should just hit Enter key.

I think you need to start fresh again. If you need help let me know.

Eugen

[Jeff Harned]

Hi Eugen,

Some good news!

Thanks for the good info!!  I deleted that config2.txt and followed your stated command to get back to the right path.  I also started fresh again as you suggested...this time not entering 2 at the Destination filename [startup-config]?  Where the consolecopy came from I have no idea!!.

I now am able to ssh after a power cycle so this is good!!!  I still have no data going to the destination units after a power cycle but I may have isolated where the problem area might be in my configuration.  As stated in the very beginning, I am using Multicast VLAN Registration in my small LAN and have found it to work well in what I am trying to do.  Below is the script for one of those destination units:

cisco2#(config-if)#interface fastethernet0/1

cisco2#(config-if)#switchport mode access

cisco2#(config-if)#switchport access vlan 20

cisco2#(config-if)#mvr type receiver
cisco2#(config-if)#mvr vlan 10 group 239.1.1.3

After I save the configuration (copy running-config startup-config), exit, cycle power, and then re-enter the switch, I retype the first and last lines from above and data now flows to this unit!!  I must be missing something??

Attached are the boot, flash, and nvram directories for a before and after powr cycle.

Thanks.

Regards,

Jeff

[ebarticel]

Hi Jeff,

Thats excelent, well done.

I still see a path in your boot output that has the forward "/" in the path.

"Private Config file:  flash:/private-config.text"

Maybe try to change this one as well and hope that will solve your 2 commands not saving in startup-config

I don't realy know why those commands are lost after a reboot, it could be just the way the switch works with ports assigned to multicast groups.

Eugen