Networking

A few days ago, I got the last month's Internet Bill. And due to overusage I had to pay 4 times the usual. That's when I realized that I definitely need to keep a check on my Internet usage. Vnstat is a simple console based tool built for such purposes. It keeps a log of the network traffic for the selected interface(s). It can show the usage stats in various formats (daily, monthly even live mode is available). It has proved to be a real life(actually money  ) saver for me.

Alright! So this one day, I'm talking to a friend. She's telling me about this real cool movie she heard about...2012 or something (which btw... WATCH! ). Now I'm also typing my password on an ssh server, and I happen to mistype. Now I have a feeling I've done so, so I press Backspace till I think nothing could ever have lasted here and type again. My lucky day it was, for I happen to mistype again. That was when it hit me! There's gotta be a way around this password thingy. This is why I love being a Linuxer. There's always a way out of everything!!!

I have been using Nmap for a long time now. It is a really good command line network scanning tool. I use it for almost all my scanning needs. There is also a graphical frontend available, Zenmap. It has a simple interface with some pre defined commands and provision for entering commands manually. But the feature I like most is its ability to draw topologies. Run traceroute for different IPs and it will draw a Network Topology for you.

Sometimes we want to connect to a machine using SSH but can't because it is behind some firewall or NAT router. This is a common situation when you want to connect to office computers which are usually behind a firewall or NAT router, from an outside computer. Reverse SSH tunnelling is a way to  do so. In this article we will set up a Reverse SSH tunnel.