Mad Router

I have written a script in python, always with scapy, that captures in real time all the Telnet traffic accross the network.

The script, when reduced to its minimal needs, has 18 lines …

Here is the video.

All the datas captured are stored in a file: Client-Source IP - Server-Destination IP

The script does not manage very well when several telnet connections are launched to the same Telnet server by a unique host.

For 2 days, i’ve been working on a topology about inter-vlan routing, all in an emulated environment, Dyna(mips/gen) + two tap interfaces as my nodes.

tap0 in VLAN 2, tap1 in VLAN 3 , VLANs on the same switch ( 3660 + NM-16ESW as my switch), dot1q link between switch and router… bla bla bla

Well, it didn’t work, can’t ping each tap from another, so what’s going on ? I checked my configuration twice… then three times, then four…. then search for some tutorials about inter-vlan routing… ( oh my god :s ) but always the same problem…

So i’ve just check those two tap interfaces on the same switch trying to ping each from other!

debug ip packet , debug ip icmp… always nothing…

Why not try arping? let’s go, debup arp…. always no response…!

Well I finally capture the traffic… and what did i see ?

From both sides of the switch… no trace of any ARP response… the tap interface didn’t want to tell what was its MAC address to fill the CAM table

If any has an answer about this… I’m ready to hear it!

As SCTs, we have to use an Epson Projector to display our slides in Supinfo, unfortunately, it’s only Wind*ws compliant.

This night, I’ve just found a way to keep my laptop under Linux and use the Tablet PC in order to display my linux programs on the wall.

I connect the Tablet PC ( Windows XP ) to the Epson projector and use a ssh connection between my laptop and the Tablet PC to forward the X Window display.

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Par défaut, Dynamips va prendre toutes vos ressources CPU lorsqu’il émule un ou plusieurs routeurs, un peu gênant quand vous faites plusieurs choses à côté et encore plus quand vous émulez 8 routeurs

Comment faire pour ajuster les besoins de dynamips autant en CPU qu’en RAM ?

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Si toi aussi tu es pauvre, tu dépenses tout tes sous dans ta scolarité à Supinfo , tu n’as pas les moyens de te payer un Lab CCNA, voir CCNP, et tu as envie de manger du router jusqu’à penser en binaire, alors cette article est fait pour toi.

Installons ensemble sous linux, Dynamips et Dynagen, 2 merveilleux outils symbiotes!

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