[Workaround and Fix] - Power given, but Power Controller does not report Power Good - Cisco 2960X Stack

If you hit this page, I think you have encountered an issue similar to what I have faced in my production environment yesterday. But still let me give you a brief about what I had seen so that you can compare it with your problem and apply the fix if needed.

Problem:-

Couple of PCs which were connected to our access layer switch WS-C2960X-48LPS-L were continuously flapping. It was not the link flap, but a POE related flap. Look at the strange alerts on the interfaces,

%ILPOWER-3-CONTROLLER_PORT_ERR: Controller port error, Interface Gi1/0/32: Power given, but Power Controller does not report Power Good
%ILPOWER-7-DETECT: Interface Gi1/0/32: Power Device detected: IEEE PD
%ILPOWER-5-POWER_GRANTED: Interface Gi1/0/32: Power granted
%ILPOWER-5-IEEE_DISCONNECT: Interface Gi1/0/32: PD removed
%ILPOWER-7-DETECT: Interface Gi1/0/32: Power Device detected: IEEE PD

Solution:-

This just kept happening again and again. Though the device doesn't need POE, it appeared to be related to POE negotiation. So as a workaround I just disabled POE on the interface using below command after which the alerts just disappeared.

Switch(config-if)int g1/0/32
Switch(config-if)#power inline never

And when we checked with Cisco for the solution, they said it is a hardware fault and raised RMA for the device. 

I hope this piece of information was useful for you.

[Fix] GNS3 IOU Error - Error while creating project: Client version 1.3.13 differs with server version 1.3.3

This post will help you to understand why we receive the below error and how to solve it. Even if you get different numbers, this solution will work.

=> Error while creating project: Client version 1.3.13 differs with server version 1.3.3

The IOU VM version number must match with the version number of the GNS3 software. If your IOU VM is running a different version of gns3 than your client, you will get that error message and will have to fix it. You have 2 solutions, One is to degrade your GNS3 to your IOU version. Other one is to upgrade your IOU version to match the GNS3 version.

Solution 1:  Identify the version of your IOU. For example, if it is 1.3.3, you will have to download the same (1.3.3) version of GNS3 as well.

If you want to download a specific version of GNS3, please visit https://github.com/GNS3/gns3-gui/releases.

Solution 2: If you prefer to use a newer version of GNS3, you can upgrade your old IOU VM to the newer version.

This is normal that whenever you upgrade your gns3 you also have to update it on the IOU VM. Its easy, with the IOU VM powered off,  edit its network settings to attach to "NAT" - so it can go out on the internet to update. start the VM, log on as root, pasword cisco and enter the following command:

pip3 install gns3-server==1.3.13

1.3.13 is the version of GNS3 (Use the version that you need), so I want to upgrade my IOU to the same version. Once you run the command, it should download and install the update. all sorts of warnings will flash by the screen but that doesn't matter as long as the last line says something like: "Install of gns3 was sucessful" now to shutdown your vm - use the command

shutdown -h now

once shutdown,  edit its network settings to attach to "Host-only Adapter", fire it up and you should be able to connect to it and use run IOU images (as long as you remembered to upload them to the new IOU VM.

I hope this helps, Let me know your comments.

How to install Regional languages in Windows 10 - Tamil | Hindi

This post will let you know how to install Tamil or any other regional language that you use in your Windows 10 machine. In Windows 7, I was able to view Tamil fonts in Chrome, IE and in other in-built apps. But after upgrading to Windows 10, I could not view these Tamil fonts in any of my apps. I did a little search, found a fix and I am going to share it to my fellow Tamil folks!

Before I start, Let me tell you why it's not working in Windows 10. Windows 7 had some pre-installed Tamil fonts like Latha and Vijaya by default. But in Windows 10, these fonts had been moved to a pack called "Supplemental Tamil Fonts" which is marked as a Optional feature. So enabling this optional feature, will help us to get our language back.

Follow the below instructions to enable Tamil letters on Windows 10,

Click the Start button.
Click Settings.

In Settings, click Time & language.

Click Region & language.

All regional fonts to your country will be listed, If Tamil is not included in your languages, click the "+" icon next to Add a language.

Scroll to find Tamil, then click on it to add it to your language list.

That's it! You should be able to read your Tamil articles. :)

[Solved] Chrome - Netflix not working | WidevineCDM not updating

Run the Chrome application as Administrator- This might solve the issue, If it doesn't follow the steps given below.

Fix that worked for me was to delete WidevineCDM from my Chrome folder, which allowed me to update Widevine under Chrome://components, and then go to Chrome://plugins and ensure that Widevine was enabled.

To delete WidevineCDM follow these steps. It may seem complicated but it's actually really easy and you can do it :D

If using Chrome and Windows 8.1:

Step 1:

Close the Chrome browser then press Windows Key + R to bring up the "Run" menu.
Type %userprofile%/appdata

Step 2:

When the window opens, click Local, then click Google, then click Chrome. Find the WidevineCDM folder and delete it.

Step 3:

Press Ctrl+Alt+Del and open the Task Manager.
Right click on anything that says chrome.exe and choose end task. There may not be anything to click on, that's fine. If running Windows 8.1 you can click 'Name' near the top to sort everything by name to make it easier to find. Close Task Manager.

Step 4:

Open Chrome. Go to chrome://components 
You should see Widevine at the top, click update. It should now update to the current version. Once it's finished (it only takes a moment)...

Step 5:

Go to chrome://plugins
Make sure that Widevine is enabled.

Step 6:

Launch Netflix again. Try to play a video. It should work now. If not, then there is something else going on and I apologize if I've wasted your time.

[Fixed] Touch screen not working in Chrome - Windows 10 & 8.1

Windows 8 and Windows 10 has a lot of in built apps and games that supports touch events. Unlike Edge and IE which are default browsers in Windows, Chrome a browser that is not designed for touchscreens. It does not mean that it doesn't support touchscreens, but the features that supports touchscreens are hidden.

These touch screen features and add ons of Google Chrome are still under experiments and hence these features are disabled by default. This post will help you understand how to enable these hidden features. Let's start right away..
Create a new tab and type the below address in the address bar of the browser.

chrome://flags

Press Ctrl+F and search for 'touch'. This will list down all the experimental features that has the keyword touch in it.

Look for below flags,

Enable touch events

Touch Optimized UI

Enable touch initiated drag and drop

These flags are set to Automatic by default. You have to change them to 'Enabled' to make touch working properly.

For better touch experience, you may want to download Chrome Virtual Keyboard . This will improve form filling and other normal typing process inside Chrome.

I hope this helps, thanks for visiting!

[Solved] Server has a weak ephemeral Diffie-Hellman public key | Chrome Firefox Opera

I write this post in order to let you know how to resolve the 'Server has a weak ephemeral Diffie-Hellman public key' error. This error mainly occurs on browsers like Chrome, Firefox and Opera while you try to access a less secured page. Follow the steps below to solve this error in Firefox browser.

Firefox Users:

Type the URL given below in your browser's address bar,

about:config

Here in this config page, you will find a list of boolean entries. Search for below two entries,

security.ssl3.dhe_rsa_aes_128_sha

security.ssl3.dhe_rsa_aes_256_sha 

By default, these are set to TRUE. But you have to set them to FALSE in order to allow the less secured pages.

Chrome and Opera users, 

1) Instead of using HTTPS try using HTTP. For example,

Use http://letusexplain.blogspot.com instead of https://letusexplain.blogspot.com

2) If it doesn't work in http, you may have to use IE Tab extension to view only this web page in Chrome, This extension allows you to open a particular website on IE without exiting Chrome.

Once installed IE Tab, type the URL you want to visit on the Address bar of chrome.

You will see the error message, Now all you have to do is click on the IE Tab icon which you will find in the right corner of the Chrome window (Highlighted in Blue).

This would allow you view the web page without any issues. Though it's not an official fix, it still works.

I hope the steps given above solves your issue, Let me know if this helps.

[Solved] Error relaunching VirtualBox VM Process: 5 | VirtualBox won't start

In this article we are going to discuss about the 'supR3HardenedWinReSpawn' error. When i was exploring the Cisco IOU tool, I had to import a Cisco IOU VM which was in OVF file format. But as soon as i double click the ovf file, VM refused to start and an error popped up, saying:

Error in supR3HardenedWinReSpawn

Result Code: E_FAIL (0x80004005)

Component: Machine

Interface: IMachine {480cf695-2d8d-4256-9c7c-cce4184fa048}

Error relaunching VirtualBox VM process: 5

Command line: '81954AF5-4D2F-31EB-A142-B7AF187A1C41-suplib-2ndchild--comment Fedora32 --startvm fd699e30-a77b-4eac-8ced-1210d756855d --no-startvm-errormsgbox' (rc=-104)

The error that you receive might not be as exact as it's given here, since VM details are also part of the error. For example,

If you look at the error shown above, My VM name 'GNS3 IOU VM' is also part of the error. 

Why do I see this error ?

Well, When i was doing a little research on this topic, i found out that this error might show up because of any one of the below points. 

1. It could be an issue with the VirtualBox version that you are trying on, I found the latest VirtualBox version 5 to be very buggy. 
2. It might be your Antivirus which causes this error.
3. It might be because of your registry settings.

How to resolve this E_FAIL (0x80004005) error ?

Try the below solutions one by one,

Solution 1:

Find the below entry in Registry Editor and delete it.

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers] "C:\Program Files\Oracle\VirtualBox\VirtualBox.exe"="DISABLEUSERCALLBACKEXCEPTION"

Solution 2:

Uninstall or Disable your Antivirus software.

Solution 3:

If the above 2 solutions did not work, Try degrading the degrading the VirtualBox to version 4.3.12 from the version that you are currently running. You can download VirtuablBox 4.3.12 from this link. https://www.virtualbox.org/wiki/Download_Old_Builds_4_3_pre24

If you still face this issue, I would recommend you to try the other desktop virtualization softwares like Vmware Workstation or Hyper--V.

I hope this post helps you to solve the mentioned error. 

[Solved] GNS3 1.3.7 not working | black screen python error while launching

What's GNS3?

GNS3 is a software emulator that is widely used by network professionals to practice real life network scenarios and to study for cisco exams. What I love more about GNS3 is it's community developers. These guys regularly updates this emulator software to add newly released devices and to reflect new standards and more features. More over this is best network simulation software that is available in the market for free of cost.
Let me explain what was this black screen error and how i fixed it!

GNS3 version 1.3.7 black screen Error

Just to explore what's new on GNS3 version 1.3.7,  I downloaded GNS3 1.3.7 from official GNS3 website and installed it on my machine (I'm running Win 8 x86 machine) with all the supporting tools like Wireshark, Solarwinds and Winpcap.

But the moment I try to launch my GNS3.exe application it showed up an extremely brief command prompt window, and suddenly the window disappeared within two seconds and then nothing happens. I uninstalled it and reinstalled it again, same issue. I can glimpse some kind of C:/python Failed messages but the command prompt window disappears so incredibly fast I can't even screenshot it.

How to resolve this GNS3 Python error ?

Let's come to the actual point, To capture the error we will have to launch the GNS3 through command line. To launch the GNS3 software through command line, we may have to open command prompt by pressing Win+R and typing cmd and pressing enter key. Refer the snapshot below,

Once you have opened the command prompt window, open GNS3 installation folder by using cd command. In my case it is, cd C:\Program Files\GNS3. Run GNS3.exe from that folder, below snapshot would give you a better idea of what I am trying to say,

Now it will show us the python error which we want to capture for further troubleshooting,

File "C:\Python34-32bit\lib\site-packages\cx_Freeze\initscripts\Console.py", l
     ine 27, in <module>
       File "gns3-gui/gns3/main.py", line 39, in <module>
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2237, in _find_a
     nd_load
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2226, in _find_a
     nd_load_unlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1191, in _load_u
     nlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1161, in _load_b
     ackward_compatible
       File "./gns3-gui\gns3\crash_report.py", line 32, in <module>
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2237, in _find_a
     nd_load
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2226, in _find_a
     nd_load_unlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1191, in _load_u
     nlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1161, in _load_b
     ackward_compatible
       File "./gns3-gui\gns3\servers.py", line 29, in <module>
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2237, in _find_a
     nd_load
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2226, in _find_a
     nd_load_unlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1191, in _load_u
     nlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1161, in _load_b
     ackward_compatible
       File "./gns3-gui\gns3\qt.py", line 43, in <module>
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2284, in _handle
     _fromlist
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 321, in _call_wi
     th_frames_removed
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2237, in _find_a
     nd_load
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2226, in _find_a
     nd_load_unlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1191, in _load_u
     nlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1161, in _load_b
     ackward_compatible
       File "ExtensionLoader_PyQt4_QtCore.py", line 22, in <module>
       File "ExtensionLoader_PyQt4_QtCore.py", line 14, in __bootstrap__
     ImportError: DLL load failed: The specified module could not be found.

From the above logs, It is clear that there is something wrong with Python modules. And when I checked for the file "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py" it wasn't there at the specified location.

Hence downloaded the Python 3.4 software from Python official site and installed it in my machine. Guess what? My GNS3 started working fine now.

Try the same on your machine to resolve the issue, You can download the Python software from below link,
https://www.python.org/downloads/release/python-342/
I installed version 3.4.2, but you can try installing any version of Python. Ultimately it should solve the issue.

Also when i checked with my colleagues, I came to know that this python error occurs in other versions of GNS3 like GNS3 1.3.4 and 1.3.5 also. The same steps which are given above is applicable for all the versions & it should resolve the issue.

If you have any queries, Please do let me know through below comment section. Will surely try to help you!

[Solved] GNS3 Error - 206 Unable to create UDP NIO

In this article, I am going to tell you how to resolve the 206 UDP error. I was so irritated to see this "206 Unable to create UDP NIO" error while trying to open any saved topology. The error looks like below,

Centreon - Add Host or Router and monitor bandwidth utilization

In this article, We will be walking through the Centreon configuration steps. You will be answered to the following questions while going through this article.

1) What is Centreon?
2) How to add a router/switch/host/server in Centreon?
3) How to monitor a network device's (switch or router) interface bandwidth traffic usage using centreon?
4) How to install Centreon ? Installation steps for Centreon, etc.,
5) Centreon vs nagios, Which is better?
This is basically a Centreon tutorial page for beginners.

What is Centreon?

Centreon is a Automational monitoring system based on Nagios engine. With this great tool you can generate bandwidth reports, availability reports, ping reports, etc.,

Created in 2003, Centreon is an Open Source software package that lets you supervise all the infrastructures and applications comprising your information system.

The only problem i found with this tool is support. You don't get any support, not even a forum or a proper guide for configuration in google. Anyway this page will make you clear on Centreon configurtions.

Here We Begin

For step by step Centreon installation, I recommend you to visit this official page http://documentation.centreon.com/docs/centreon/en/latest/installation/index.html.

Once you have installed your Centreon Monitoring engine, you have got add services and hosts to be monitored. To make you clear, it is not a inventory tool to discover hosts. You have to manually add all the hosts and services for each host.

Basics on Centreon Configuration

I hope you know the way to configure pollers. Pollars are nothing but a server placed on a brach office or someother location from where you are going to monitor the devices. 

Before adding a new host, I recommend you to do the following tasks.As part of this tutorial page, I am going to add a router and monitor bandwidth of one of it's interfaces. For availability you can use ping service. Here I am using Check_centreon_snmp_traffic script. I found this on the following path of my server /usr/lib64/nagios/plugins. I verified the script with the following command.

To know how to use this script/service, check it's man page or help. Give you hostname where i've painted with red and community string in place of blue. You can add your interface name and other information also.

Check_Centreon_SNMP_Traffic

Now I am going to modify the centreon's command page according to my needs. For example Centreon considers public as the community string for snmp protocol. Also has it's default parameters to be considered. So it's better to change the command line as we need.

Refer the below image, I have changed the default arguements. I need only interface name as input. Also graph template has been changed to Traffic as it's going to be a bandwidth monitoring.

Now save this, and add a new host with the following details.

After this stage we can create our service template. Same service template can be used for multiple hosts. Here I have called my check_centreon_traffic command.

I am changing the graph template to Traffic in the below image.

Now you got to map your service template to hosts as below.

For example, I have 5 routers and 3 switches. In my case all these network devices has FastEthernet0/0 interface. So I will create a service for FastEthernet0/0 interface traffic and will map that to all these hosts.

That's over, We have created a RTR host, and mapped service interface traffic to it. Not to forget restart Centreon Nagios in the confiuration tab after doing each and every configuration. Now, you should be able to monitor your bandwidth usage and other things after readind this article.

Please post your doubts in comment box, if any.