Archive for the ‘en’ Category

Telenet modem and Cisco switch [en]

mardi, avril 25th, 2017

This is one thing among many others i have to say against Telenet: once the modem reboots (and it can be quite often, always requested by Telenet), the port of the switch just shuts down and block all access to the modem. Very embarrassing…

Let’s see what’s going on in the switch via the serial console:

Switch#show interface status err-disabled

Port Name Status Reason Err-disabled Vlans
Fa0/23 err-disabled loopback

Something you need to know about the Cisco is that the switch send keepalive packets down all active ports. When the modem reboots, it’s echoing the keepalive packet back to the switch. The switch freaks out and disable the port, cutting you off the internet.

The solution is pretty easy: all you need to do to is to turn off keepalives for that interface:

Switch#config t
Switch(config)#Interface fa0/23
Switch(config-if)#no keepalive
Switch# copy running-config startup-config

Now that we disabled the keepalive,it’s time to re-enable the port. You have to manually shut it down and re-enable it to clear the err-disable state:

Switch#config t
Switch(config)#Interface fa0/23
Switch(config-if)#no shutdown

Enjoy your recovered internet. 🙂


Getting started with Juniper SRX platform [en]

vendredi, janvier 6th, 2017

I started to play with the Juniper SRX platform a few month ago. I got a SRX 220 on loan from Rafael and i bought a SRX100 for my experimentations. The JunOS operating system installed on the boxes is heavily based on FreeBSD, so we’re in familar Unix-land. This is going to be fun. 🙂

I have access to lab documentation, but i will not exactly reproduce the setup from the books: there will be some adaptations (mainly about port numbering) that will fit my lab setup, since I will work on those devices from a remote location and i will not enjoy 100% physical access during my exercises. To make matters even more interesting, i still have my old ADSL connection that will be used as a separate internet access.

The default configuration is a simple NATing firewall/router, similar to the one you might expect from a stock OpenWRT installation. There is a web interface, but i will just ignore it, so let’s dig out the Cisco serial cable and connect to the console port.

Configuring the SRXes over serial port is nice, but they are available only in limited quantity on my Terminator server, so we will start by setting up the devices for a more convenient ssh access from my home network. The config statements allow for comments: they start with the character ‘#’ and the commands will be peppered with them, so you can copy-paste huge blocks of text at once.

We will start with the SRX100: the management port is connected to port 7 on the firewall

# Set system root password (REQUIRED)
set system root-authentication plain-text-password 

# Check if config passes
commit check 

# Remove interface from bridge
delete interfaces fe-0/0/7 unit 0 

# Add ssh pubkey
set system root-authentication ssh-rsa "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC98TAUD9PPuzRj5uyHWlxZiXGLm1JI7T2hPNwmW9pU5V/guoJ90VTNQ7lugEoX8HYxB7JC0/RA5ogJBkhcQHIAMIGT6yM7F2zzVv9LadbiMU0KrB2dZVmPKKxi49uqqj+d8zIWTbm4tLf7xdF42kr7c2AUl1kYzaD1ymlAXSavvHTg7y/h2/mZ36F7WZmVwa7Q6iI5Vuca66lauwGgl1ETS2lwneQn+CWDZFMSFDT9TmphR8mpISi8063oTwvvHa/t0bpeQnKltg1iqM2YGTlIGTgXuEWsiAARfF96zhOUAXseA9WHeCTDUITmycFau4+ILxVH47Z6oC11W52BtwIf frederic@pekko"

# Set IP address
set interfaces fe-0/0/7 unit 0 family inet address

# Put interface into mgmt zone and activate services
set security zones security-zone mgmt interfaces fe-0/0/7.0 host-inbound-traffic system-services http
set security zones security-zone mgmt interfaces fe-0/0/7.0 host-inbound-traffic system-services https
set security zones security-zone mgmt interfaces fe-0/0/7.0 host-inbound-traffic system-services ssh
set security zones security-zone mgmt interfaces fe-0/0/7.0 host-inbound-traffic system-services ping

# save changes

# From now, ssh is available and we can disconnect the serial interface. It won’t be used for the rest of the experimentations unless we need to move the management interface to another port. Now, let’s set up PPPoE…

set interfaces fe-0/0/0 unit 0 encapsulation ppp-over-ether
set interfaces pp0 unit 0 ppp-options chap local-name <YOUR_USERNAME>
set interfaces pp0 unit 0 ppp-options chap default-chap-secret <YOUR_PASSWORD>
set interfaces pp0 unit 0 pppoe-options underlying-interface fe-0/0/0.0
set interfaces pp0 unit 0 pppoe-options client
# When using PPPoE, always set MTU to 1492
set interfaces pp0 unit 0 family inet mtu 1492
set interfaces pp0 unit 0 family inet negotiate-address
# Explicitly tell to use the PPPoE interface as default route
set routing-options static route next-hop pp0.0 metric 0

At that point, the PPPoE session is established. Let’s check it:

run show interfaces terse

pimd up up 
pime up up 
pp0 up up
pp0.0 up up inet -->
ppd0 up up
ppe0 up up
st0 up up
tap up up
vlan up up
vlan.0 up up inet

This looks good ! We have an IP address from our ISP ! Let’s attack the SRX220…


Ikea hack: The candle spill guard [en]

samedi, février 21st, 2015

My girlfriend bought a huge candle holder some time ago. Unfortunately, she has a carpet on the whole floor and the candles tend to drip their wax on it, which makes a terrible mess that stick like hell and is a real bitch to clean up.

We could not find any suitable protection in any shop around, until I went to Ikea and I found this.

Carpet protection for desk chair

Okay, I would have preferred something circular instead of a rectangle, but the shortest side length was exactly what i needed. Given the price, i bought two of them and used one under my desk chair, the other was left to be butchered. 🙂

Finishing the cut

Finishing the cut

I marked the center of the sheet and made a hole small enough to snugly fit a small nail. Then the whole thing has been nailed to the side of my table because i lacked some clamps. Of course you will ruin your table doing so, but it was the most reliable way for me to have the roundest shape possible. You should use a piece of scrap wood and extra clamps if you value your table. 🙂

Dremel tool

This is not a drill bit


The cutting rig: detail of the "rail"

Detail of the « rail »

Detail of the cutting rig

Detail of the cutting rig: Yes, Dremel, Club Mate and Gaston Lagaffe mix quite well 🙂

The leftovers of the cutting

The leftovers of the cutting

After that treatment, the resulting disc had the edge sanded down to remove plastic shavings and it now look like it was coming straight from the shop.

The finished product in action

Discrete yet effective

This is an old hack that was done 4 years ago. It still look fine today. – 10 years already ! [en]

mercredi, avril 2nd, 2014

Today marks the tenth year of this domain, but my website existed already a year ago under a different name.

Lots of things happened, and the infrastructure evolved with the knowledge gained, while fooling around and screwing up things, here is a timeline of events:

  • 2003: started operating from a small ADSL line at home
  • 2004: Domain entered my possession, Zoneedit was handling the DNS zone and the mail reception
  • 2006: First IPv6 experiments, starting with my girlfriend’s home, using a SixXS tunnel
  • 2007: Playing around with a virtual machine running on somebody else server, no great result, service got shut down
  • 2008: First dedicated server at OVH
  • 2009: Dedicated server replaced by something beefier, IPv6 appeared, Partial SSL appeared with a CACert certificate
  • 2011: Joined the DN42 project to learn more about BGP routing
  • 2013: Due to Zoneedit failing to provide IPv6 on their name servers, their US-centric approach, and the Snowden case, i am now handling my own DNS and Email became self hosted.
  • 2014: In the process of replacing the current server, after 5 years of operation, it is time to move on to fresher hardware

The future:

There are many plans in the boxes for the future. The most immediate one will be to replace the SSL certificate by a paid one and go full SSL by default, then i plan to make the infrastructure much more resilient by distributing it: i don’t like the idea of having everything in the same place, even if i have backups. Downtime will hurt.

Mid-term project will be having my own personal cloud, and the long term one will involve AS numbers. 🙂

A puzzle solved. [en]

mercredi, juillet 4th, 2012
Vasco Digipass 810

Vasco Digipass 810

Do you remember when i opened my bank calculator ? Beside replacing dead batteries, i wanted to see what made it tick and eventually replace it by an ordinary smartcard reader and some code running on a computer.

Turns out that other people had the same idea, but they beat me by having put more time and energy into that project and ended up producing something usable.

It’s just a Python script to talk to the card. The usage is very straightforward, here are some examples:

To authenticate with the M1 key and the 23543696 challenge, type the following command:

$ ./EMV-CAP -m 1 23543696
Using this software for real financial operations can lead to some risks.
Indeed advantage of using a standalone reader is is to isolate your banking
card from big bad malwares.
Using it in a non-secured reader is taking risk that a keylogger intercepts
your PIN, a malware accesses to your card informations, or even intercepts
your transaction to modify it or operates its own transactions.
Are you sure you want to continue?
If so, type 'YES', or anything else to quit:YES
Enter PIN (enter to abort) :
Response: 45108749

To sign a transaction the same way than the M2 key with the challenges 09356196 and 345, use the following command:

$ ./EMV-CAP -m 2 09356196 345
Using this software for real financial operations can lead to some risks.
Indeed advantage of using a standalone reader is is to isolate your banking
card from big bad malwares.
Using it in a non-secured reader is taking risk that a keylogger intercepts
your PIN, a malware accesses to your card informations, or even intercepts
your transaction to modify it or operates its own transactions.
Are you sure you want to continue?
If so, type 'YES', or anything else to quit:YES
Enter PIN (enter to abort) :
Response: 45201783

Thank you Jean-Pierre Szicora and Philippe Teuwen, nice work !! 🙂

An update to the wall wart hunting [en]

mercredi, avril 4th, 2012

There was some evolution since that article.

Velleman PSIN30012 with some desk clutter

The Power supply: a Velleman PSIN30012

power supply with brackets

I can has brackets ?

I finally decided to make the brackets and installed the power supply in my apartment.

The power supply can output 25A under 12V, should be enough for my applications at the moment.

I pulled some 6 mm² wires through my apartment, inside the same conduits as the network cables. There is one supply going to the datenklo (the toilet host my network, like at the Chaos Communication Camp) and two independent supplies are going to my desk. They only meet at the terminal blocks.

The power supply has been installed in the cupboard near the fuse box and is protected by a 6A breaker at the primary, sharing the circuit with the doorbell.

power supply in place

Installed and wired

6 mm² wires on the power supply

6 mm² wires on the power supply

temporary cable with XLR 4 pin female connector for the wireless router

Temporary cable with XLR 4 pin female connector

The connectors i use for the 12V power sockets are Neutrik XLR 4 pins, they are much more resilient and safer than cigarette lighter plugs (will be part of a rant in a separate article)


None so far, the power supply is running smooth and cool, but the fan is noisy like hell !!

My wireless router is running from that power supply and seems very happy about it.

The future

  • I will have to move the power supply to the datenklo: i have a noisy 24/7 ventilation in there. 🙂
  • Still need a way to integrate the XLR sockets with my light switches in such a way that it look like it’s coming straight from the manufacturer. Will be part of a separate article. 🙂
  • Rebuild my media-PC to work straight from a 12V DC source.
  • Connect LED strips to it: my bar and my kitchen will receive a bunch of LED strips.
  • Figure out how to work with pictures in WordPress, this article is a mess !!

Is there such a thing as « hackerspace burnout » ? [en]

samedi, janvier 28th, 2012

After the awesome Chaos Communication Camp 2011, i had some difficulties to get involved with projects in the space for about a month and half: it’s like i lost something.

To put in context, i’ve been co-driving the truck that carried the material and luggage of 3 belgian hackerspaces and one dutch space up to Finowfurt and back. My co-driver did all the paperwork for the truck, made the whole pickup schedule, did the initial loading at the starting point, and even did the cooking every day since we arrived at the camp, while also taking care of his son. Hats off to that guy that will certainly recognize himself when reading this. On my side, i was busy coordinating the set up of our party tent (we barely had enough hands to raise it), doing all the wiring and light setup, and helping installing the tables and the network. The weather was not friendly either. After the camp was the teardown, packing and filling the truck, Then the driving back and final delivery to the different spaces, all on a very compressed schedule.

Now i feel the same thing again: i’ve been working in the space over the last month on a quite regular basis: drink shopping, moving shelves, filling fridge, garbage collection, rebuilding the electric installation nearly from scratch and dealing with the sharp aspects of socializing.

I want to work on my own pet projects and stop working on infrastructure and janitorial stuff for a while. For the ByteNight, i already made it clear that i will not get involved in any aspect of it. I’ll be there as a customer, sipping my drink on the sofa.

Once i finish the last missing bits on the electric installation, i will freeze all infrastructure projects (Zoppas, Parallel port interface, last power circuit and relay board) for some time.

Reboot in March 2012 ?

Wall wart hunting [en]

mardi, janvier 17th, 2012

I found in my apartment about 10 wall warts and two linear power supplies that give the same (or similar) voltage for my equipment.

Spools of red and black wire with a power supply

Let the hunt begin

I would like to get rid of those power bricks and have a more consistent and centralized setup. I hope to make some savings in the process by using a more efficient oversized switch mode power supply. Another advantage is that if i want an UPS on that line, i just need to connect a SLA battery.

My apartment will be wired with 6 mm² wires carrying 12VDC: one branch go to the networking area, the other two go to my desk.

Let’s lay down some wires !!

1 minute hackjob: bicycle light battery [en]

dimanche, octobre 30th, 2011

I needed a battery to power the front light of my bicycle last night, here is my solution. You will need:

  • A 4,5V flashlight battery
  • A zip tie
  • An adhesive pad for the zip tie
  • A nose pliers

  • Bend the battery terminals in two, crimp the hinge area.
  • Slightly lift the free side to facilitate the insertion of a wire
  • Attach the adhesive pad to the battery, slide the zip tie in the pad and attach the whole contraption to the bicycle
  • Insert the wires in the clamps you made earlier: let there be light. 🙂
If you can’t find the adhesive zip tie pad, you can still use the good old fashioned duct tape. 🙂

Summer is over !! [en]

mardi, octobre 18th, 2011

Three months of silence, but not of inactivity.

The CCC Camp was the big event in august, there are no words strong enough to describe the level of awesomeness i experienced during the camp. I needed a lot of time to prepare before and a lot of time after to bring things back to normal. It was really worth the energy i spent for that. Co-driving the truck was an interesting experience in itself. I have some video footage that still need editing.

Once i was back home, whenever there was sun shining, i wanted to be out: enjoying what’s left of it or cycling around.

With the summer now gone, i can work on the low season/winter projects:

  • Bicycle suitcase: The suitcase i carried on my bicycle got damaged after my fall in may, now i have no remorse gutting it. 🙂
  • RottenWRT router: A special VPN box for bad networks run by nazi sysadmins. It already received an internal sound card extension
  • I also have a couple of things to do at home, like finishing the network wiring, pulling a 12V central power supply, install the electricity and plumbing for a dishwasher, doing the schematics of my electric installation, a bit of cleanup and getting rid of old things.
  • Do something of the video rushes i have sitting on my disk
  • Clean up the photo gallery: it’s getting messy
  • Parallel port universal interface: I stopped working on it when BIFFF started.
  • Some hackerspace projects, like the door lock and a relay board.
  • ??? 🙂
Will the winter be long enough ?? 🙂