Completely clear a Cisco switch configuration

When you issue the "wr erase" command in order to clear the configuration of a Cisco router, the config.text file will be erased from the flash. Then when you reboot the switch, there will be no configuration. But the Vlans will not be erased from flash because "wr erase" does not delete the vlan.dat file. So if you need to delete the Vlans as well, you need to delete the vlan.dat file manually!

There is an easier but "dangerous" way to get rid of both configuration and Vlans in a Cisco switch by holding the "mode" button for 10 seconds. The LEDs on switch will flash, the files config.text and vlan.dat will be renamed to config.text.renamed and vlan.dat.renamed and the switch will reboot with no configuration and no vlan!

Cisco ASA Firewall pre-shared key in plain text

If you issue a "show running-config" on a Cisco ASA Firewall or PIX, the pre-shared keys are all hidden by the asterisks. In order to visualize the pre-shared keys, you need to issue the following command in privileged mode:

ASA# more system:running-config

Hope this trick helps...

%% Non-volatile configuration memory is being accessed, Try again later

If you get the error message,
%% Non-volatile configuration memory is being accessed, Try again later

while executing "show startup-config", is because another user is connected to the same router and has issued "show conf" but hasn't still completed.

You can find out who the connected user is by issuing "show users" or "who" command.

Certified CCNP Finally...

Yesterday I passed the final exam of CCNP certification, TSHOOT and certified CCNP finally.
The exam was much easier than what I was thinking. There was a logical troubleshooting behind every trouble ticket. I can't give much information about the exam because of Cisco regulatory but I highly recommend to check this website and practice enough before taking the exam:

http://www.cisco.com/web/learning/le3/le2/le37/le10/tshoot_demo.html

This website gives you a very good idea on what you should expect in the exam.

Best of luck to everyone...

Cisco Phone - Registration Rejected : security error

During the installation of new Cisco phones, I received the message "Registration Rejected : security error" as soon as I connected the phone. The phone was not yet configured in the Call Manager and was on Auto Registration. There was enough extension in the pool as well.
The way that I fixed the issue was adding the phone manually into the Call Manager. Then resetting the phone and it started working.

Upload IOS from ROMMon mode

Here is the steps to follow when you want to upload an IOS to your Cisco router from ROMMon mode:

You need to run the TFTP server on your PC. Connect your PC to LAN port of your router, configure your PC with the IP address which is assigned to the TFTP server (192.168.16.19 in this example) and type the following commands:

CUBAC “database update error”

While adding the Speed Dial  numbers to your CUBAC version 3.1, you may get “database update error” error message. On Cisco website  the solution is disabling the Antivirus. If by disabling the Antivirus it still gives you the same error message, you only need to reboot your Auto Attendant Console server. The reboot will fix the issue.