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{ Category Archives } Networking

Plot Pings With Gnuplot

Recently I was discussing some problems occurring on my landline with my ISP’s customer service, and some connectivity issues that they couldn’t fix. After sending them a couple of traceroutes, pings, router logs, I also decided to plot some of the data for them, because they seemed having difficulties to spot the problems. So I […]


SSH known host on OSX

To manage my multiple machines and test computers on my local network I use SSH, and often after reinstalling a test machine I want to connect back by SSH and my Mac just pops me back this message :

I usually find this message quiet annoying, but knows the commands to avoid this problem, […]

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PPTP VPN With Debian (add button disabled)

Today I had to create a PPTP VPN in a Debian virtual machine, therefore I installed the following packets :   $sudo apt-get install pptpd $sudo apt-get install pptp $sudo apt-get instapp network-manager-pptp but when I tried to add the VPN ( in System -> Preferences -> Network Connections ) the “add” button was disabled. […]

Create a VPN in Packet Tracer

This is a brief “Sample configuration”, to create a VPN in the Packet tracer v5.3 Step 1: Add two routers 2811 Step 2: Here are the configuration files.

And the Second Configuration :

This works perfectly, and it is a good start for someone who wants to create a VPN on Packet tracer. […]

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Bypass a Blocked NAT

A few years ago, I was staying in a student accommodation, where I had to pay to connect devices to the internet.  Since I was doing a Master in Computer Science, I had many devices to connect and decided to buy a router / switch Cisco Linksys E2000 and use the Network Address Translation to […]

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UDP Flooder in C

Yesterday we where still working on some attacks on our  bench test  and we tried some exploits on IP phones that we found on the internet. Most of them where making DOS or DDOS on the phones, this means that the phones were basically freezing.  Then we made some modification to a C UDP flooder […]

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Who’s connected ?

To know who’s connected on your computer use the following commands : Commands : who : show the connected users : Linux/Mac last : show last connexion (passed ) : Linux / Mac lastb : show last connexion (failed) : Linux These files may also contain clues :

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How to know my public ip address with bash

this is a little bash script to know your public ip address

That’s it.

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E-mail SSH Connections

This solution applies if you want to receive an e-mail when one connects to your server via SSH. open a command line and type in :

at the end of the file add the following command :

When one will now connect to your server, you will receive an advertisement e-mail.

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