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Showing posts from December, 2014

Time Domain Reflectometer (TDR) for Network Professional

As a network engineer/administrator, you would encounter the cabling problem of patch panel to host, patch panel to switch, switch to switch. In these scenarios, you can determine whether switch or physical layer (Layer 1 ) issue or not before contacting to cabling contractor. To do so, you can use below commands. show interface show interface counters show interface counters errors Moreover, you still can find the cabling issue with another testing method. That is Time Domain Reflectometer. To test this in cisco switch, use below commands. test cable tdr interface   port number show cable-diagnostics tdr interface   port number You will know how to use it from below sample pictures. If you are testing FastEthernet, Pair A and Pair B result must be Normal. If you are testing GigabitEthernet , all Pair must be Normal. Other than that result, you need to find out where is the distance that cable becoming fault. The approximate cable fault distance is sh

Deploying Legal Notice Logon Banner in Domain Computers

As of Audit Purpose or Standard Organization Policy, we need to deploy legal notice logon banner message/warning of usage logon message in domain computers. To do it automatically, we can use logon script/group policy. Since group policy is easy to mange, I'd like to show you how to do it. Open group policy management console, go to group policy objects, right click on it and select new to create new GPO as below. (You can create and link directly on the OU that you wish to deploy GPO but I create it separately to show clearly.) Right click on newly created GPO and select edit to make changes. Go go Computer Configuration>Windows Settings>Security Settings>Security Options> and find Interactive logon: Message tesxt for users ... . Enable and define the message that you wish to show as logon message. Find Interactive logon: Message title for users attempting... and Define the message title for your logon message. After that, link newly crea

Upgrading the Cisco Switch IOS

According to business need, you will need to upgrade the OS of your network device in your infrastructure as a Network Administrator/Engineer. I’d like to share the experience of upgrading the IOS in Cisco to the beginners and for those who haven’t done this yet. Before complete the task, you should know and prepare the following. - You must have correct IOS License for your devices - You must have backup of current running configuration and IOS. - You must have Local/Remote TFTP Server/FTP/SFTP Server to keep backup files and new IOS. - You should prepare pre-configured same model device if you have. So you can replace if your task was something wrong. - Upgrading task should do in Maintenance Windows. You shouldn’t do it however you have very good hands-on experience for that. - You should read Tech Notes from Cisco about Bugs for your new IOS before upgrade. Then you can expected what need to be done if something unexpected issue occur. - Be ensure the role

Solving "WSUS administration console was unable to connect to the WSUS Server via the remote API" error

Today, I've got below when I try to connect my WSUS Server via WSUS Console. Below logs are display in Event Logs too. The WSUS administration console was unable to connect to the WSUS Server via the remote API.  Verify that the Update Services service, IIS and SQL are running on the server. If the problem persists, try restarting IIS, SQL, and the Update Services Service. The WSUS administration console was unable to connect to the WSUS Server via the remote API. Verify that the Update Services service, IIS and SQL are running on the server. If the problem persists, try restarting IIS, SQL, and the Update Services Service. System.Net.Sockets.SocketException -- No connection could be made because the target machine actively refused it 172.16.99.98:80 Source System Stack Trace:    at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)    at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, S

Putty Command Line Error - unknown option "-wt" in GNS3

You will receive "Putty Command Line Error" as below if your are using GNS3 and later version. To overcome this error, just go and download Putty.exe that provide from below link. After that , overwrite the Putty.exe in your pre-installed Putty.exe Download Putty for GNS3 Once download and overwrite the Putty.exe, you may try to console Router/Switch/Firewall in GNS3. If you want to know about for that, read details at  http://forum.gns3.net/topic5016.html May you all be happy. (Be knowledgeable, pass it on then)

Finding Server Model and Serial Number in Linux remotely

Sometime you might need Server Model Name and Serial Number for Documentation, Audit or Warranty Lookup Purpose. It's easy for Windows server to extract. But for Linux, I believe, it will be a bit busy if you are not in touch with Linux. I just want to share on how to for those who not in touch with Linux. Login to Linux Server that you need to extract information for Server Model and Serial Number. Key in below command as "root". "dmidecode -t 1" You might need to install dmidecode package if you Linux is not pre-installed or lower version. To install that, just key in below command first. "sudo yum install dmidecode" Below sample result are tried in Red Hat and Debian for your reference in command usage and output. May you all be happy. (Be knowledgeable, pass it on then)