Farzand Ali

Connecting GNS3 to Real Networks

One of the interesting things about GNS3 is that you can connect your topology to the real world. For some of your CCNA and CCNP studies you may need to run an actual Web browser or Cisco’s Security Device Manager (SDM) among others. Just connect your topology to your real PC. You could even connectContinue reading “Connecting GNS3 to Real Networks”

Installing common packages on Ubuntu

#sudo apt-get install vim #sudo apt-get install nano #sudo apt-get install screen #sudo apt-get install sysstat #sudo apt-get install iotop #sudo apt-get install openssh-server

More than 4 Network Cards in Virtualbox

:::::::To create more then 4 network interfaces on Virtual Box::::: C:\Program Files\Oracle\VirtualBox>VBoxManage.exe modifyvm SW1 –nic5 intne C:\Program Files\Oracle\VirtualBox>VBoxManage.exe modifyvm SW1 –intnet5 N3 (N3 is the name) Virtualbox supports up to eight network cards. If you look into the *.vbox you will see that there are already preconfigured but disabled. Unfortunately inside the VBox GUI we could only configureContinue reading “More than 4 Network Cards in Virtualbox”

How to Run Mac OS X Inside Windows Using VirtualBox

In essence, this method will let you run Mac OS X from inside a program window in Windows. As always, we’re going to use Virtualbox for this. It’s important to note that Windows virtualization programs do not “officially” support Mac OS X, so you will not be able to enable full graphics support. This tutorial should onlyContinue reading “How to Run Mac OS X Inside Windows Using VirtualBox”

After installing Ubuntu on VirtualBox… (Guest Additions in Virtual Box)

Virtual Box for some reason doesn’t seem to show Ubuntu in full screen mode and the display is distorted. You will have to install virtualbox-guest-additions in order to fix this issue. First, make sure you have the DKMS (Dynamic Kernel Module Support) package. In a terminal window type: Code: sudo apt-get install dkms Then, install theContinue reading “After installing Ubuntu on VirtualBox… (Guest Additions in Virtual Box)”

iperf (tool to measure the bandwidth and the quality of a network link)

Iperf is a tool to measure the bandwidth and the quality of a network link. The network link is delimited by two hosts running Iperf. The quality of a link can be tested as follows: – Latency (response time or RTT): can be measured with the Ping command. – Jitter (latency variation): can be measured with an IperfContinue reading “iperf (tool to measure the bandwidth and the quality of a network link)”

5 commands to check memory usage on Linux

1. free command The free command is the most simple and easy to use command to check memory usage on linux. Here is a quick example $ free -m total used free shared buffers cached Mem: 7976 6459 1517 0 865 2248 -/+ buffers/cache: 3344 4631 Swap: 1951 0 1951 The m option displays allContinue reading “5 commands to check memory usage on Linux”

Reverse Proxy (Reverse Proxy vs Forward Proxy)

In computer networks, a reverse proxy is a type of proxy server that retrieves resources on behalf of a client from one or moreservers. These resources are then returned to the client as though they originated from the server itself (or servers themselves).While a forward proxy acts as an intermediary for its (usually nearby) associated clients and returns to them resources accessible onContinue reading “Reverse Proxy (Reverse Proxy vs Forward Proxy)”

What is a Proxy?

Web Proxy? A proxy server is computer that functions as an intermediary between a web browser (such as Internet Explorer) and the Internet. Proxy servers help improve web performance by storing a copy of frequently used webpages. When a browser requests a webpage stored in the proxy server’s collection (its cache), it is provided byContinue reading “What is a Proxy?”

Port Forwarding

::::Port forwarding:::: http://portforward.com/ Port forwarding or port mapping is a name given to the combined technique of 1.translating the address or port number of a packet to a new destination 2.possibly accepting such packet(s) in a packet filter (firewall) 3.forwarding the packet according to the routing table. The destination may be a predetermined network portContinue reading “Port Forwarding”