Netz-AK went 39C3

This year, we had the opportunity to attend Europe’s largest hacker congress—the 39C3, the 39th Chaos Communication Congress. It is a four-day event organized by the Chaos Computer Club, held annually and now once again at the Congress Center Hamburg (CCH).

Here are three good reasons to attend the C3:

(1) Talks
A core element of the Congress—and probably the main reason for its public visibility. In the past, talks that made it into major media outlets included “We Know Where Your Car Is” (location histories of all recent Volkswagen vehicles, including those of government and intelligence employees, freely accessible on the internet), “The Electronic Patient Record Is Coming – Now for Everyone!” (severe security issues in the implementation of the largest digitization project in the German healthcare system), or “Operation Triangulation” (in which security experts from Kaspersky presented a zero-click attack on Apple mobile devices they had discovered).

Talks run throughout the entire Congress in four large halls. With more than 16,000 attendees this year, there was no shortage of content—and the limited time automatically ensures that only the most interesting submissions make it into the available slots. I personally watched, for example, “Excuse me, what precise time is it?”, in which the speaker presented and live-demonstrated various methods of microsecond-accurate network time synchronization. And of course, the “Security Nightmares” were a must again this year.

(2) Networking with other assemblies, meeting familiar faces again
Tables are set up all over the exhibition grounds—these tables belong to so-called “assemblies,” i.e., groups or associations. The C3-Nav gives a good impression of the venue—and the sheer number of groups present. When you’re not attending a talk, walking through the halls, or eating, these tables are typically the go-to place to retreat to. We were kindly hosted by the Chaostreff Tübingen—many thanks for that!

Right next to us, Selfnet e.V. from Stuttgart had their tables—the operator of the student dormitory network for Stuttgart, Esslingen, and Ludwigsburg. Two experienced members spontaneously took the time to give me a virtual tour of their dormitory network, and we talked about topics such as switch selection, Wi-Fi access points, redundancy, automation, and routing. I definitely took away a few new ideas—on the never-ending journey of continuously improving our own dormitory network.

At least two of our members also unexpectedly ran into other acquaintances—the (IT) world really is smaller than you think.

(3) Booths, hands-on events, venue, music

As can be seen on the aforementioned C3-Nav, the CCH is truly huge—and every room has its own design and music. The decoration team once again went all out and created something impressive. Many assembly tables are also used as booths, and there are small events and “self-organized sessions” you can take part in. In one of these sessions, for example, you could learn SMD soldering.

Unfortunately, there are only a few photos of the Congress—mainly because of the strict policy that you may not take photos unless you have explicitly asked every single person in the picture. This is meant to ensure a relaxed and low-pressure experience for everyone. Still, you can get a visual impression here, here, here, and here.

Many of the talks were recorded—if this blog post has sparked your interest, you’ll find plenty of content on media.ccc.de and on the YouTube channel.

Attending the 39C3 was a fantastic experience and definitely worth repeating. Thank you very much for the opportunity!

Members’ meeting 2025 on January 6, 2026

The general members’ meeting for the 2025 association year will take place on January 6, 2026.

Originally, a date in December was planned, but unfortunately there was not enough time at the end of the year.

A regular general members’ meeting is required by association law. Certain deadlines and formal requirements must be met, regardless of how full the calendar is at the end of the year. For this reason, the meeting will now be held at the beginning of January.

To avoid this situation in the future, we will probably move the general members’ meeting to the summer.

2025: an important year

2025 is a special year for the association.

It is the first year in which we have concluded the contract with the Studierendenwerk for operating the network. This means that a long-open issue has now also been formally clarified and placed on a stable basis.

Growth of the association

I am also pleased that I was able to invite 18 people to this year’s general members’ meeting.

Since the founding of the association, the number of members has therefore doubled.

It is increasingly noticeable that structure and activity in the association are slowly gaining momentum. Tasks are being distributed better, processes are becoming clearer, and engagement is growing steadily.

2025-12-07 Partwise outage of Pestalozzistr. 63

Due to an oversight on my part, I have unfortunately taken Pestalozzistr. 63 partially offline. I apologize for this. I will take care of getting you back online today.

Update: Pestalozzistr. is back online.

2025-12-07 Outage Eugenstr.

Our monitoring solutions indicate that it can no longer reach our switches in Eugenstr. The reason for this is not entirely clear; it could be due to a switch that has died of old age or to some kind of problem with the uplink.

We will take care of it today.

Update: Eugenstr. is back online – if problems are still appearant, please contact us.

2025-11-15 Exchange of Switches in Fruwirthstr. 3, 7 & 9

Hello everyone,

During the course of the evening, we will be replacing switches at Fruwirthstr. 3, 7, and 9, which will cause the internet to be down for approximately one hour at each location.

We will let you know as soon as we are done – everything should be working again by tomorrow morning at the latest!

Update 9:42 p.m.: Fruwirthstr. 3 has already been completed—if you encounter any problems, please report them as soon as possible!

Update 00:28: Fruwirthstr. 7&9 have also been swapped—and we’re back in Tübingen.

So you should all have internet again – and new switches that will last a long time. 🙂

2025-11-2 Maintenance: Hardware Upgrade Fichtenweg 1+16

On Sunday, November 2, 2025, starting at 8:15 PM, we will replace your network hardware with new equipment. This upgrade will provide you with Gigabit synchronous connectivity directly to your room.

The hardware replacement is expected to take approximately 2 hours, from 8:15 PM to 10:15 PM.

Update: We finished our work. If something is not working or you, contact us!

2025-11-2 Maintenance: Hardware Upgrade at Wankheimer Täle 9

On Sunday, November 2, 2025, starting at 4:00 PM, we will replace your network hardware with new equipment. This upgrade will provide you with Gigabit synchronous connectivity directly to your room.

The hardware replacement is expected to take approximately 1.5 hours, from 4:00 PM to 5:30 PM.

Update: We finished our work. If something is not working or you, contact us!

2025-10-15 Partial Outage in Fichtenweg 1

Around 12:10, one of the two switches at Fichtenweg 1 failed, causing most of the rooms to currently have no internet connection.

 

We are on our way to replace the switch.

Update: since 1:27 pm the house is online again. The priority to upgrade this house has been increased.

10-10-2025 Planned Hardware Upgrade in Albstadt

On Friday, October 10, 2025, from 4:00 PM to 6:00 PM, we’ll be replacing the network hardware in Albstadt with newer equipment. This will likely cause an outage of up to 1 hour per building.

If you’re interested, you’re welcome to stop by:

  • From ~4:00 PM in the basement (UG) at the main entrance of Poststraße 22/1
  • From ~5:00 PM on the 1st floor (1.OG) of Poststraße 22/2

For most of you, this change won’t be noticeable—you’ve already had Gigabit speeds to your rooms for a while.

If your connection isn’t working after the upgrade, please submit a ticket via the contact form.

Update:

The hardware change was successful. If your connection isn’t working, please use the contact form to contact us.

Gigabit? Well… (Update from September 15, 2025)

Almost two years ago I posted some numbers about how many people in our student housing actually use gigabit-capable devices. Today I checked again – and honestly, it’s not the big breakthrough yet:

Location Dec 2023 Sep 2025 Change
Geislingen 25 % 35 % +10
Albstadt 53 % 48 % −5
Sigmaringen 33 % 26 % −7

Geislingen improved a lot, Albstadt dropped a little but is still on top, and Sigmaringen is now down to only 26 %. Hard to say if this is a real trend – the measurement happened during semester break, so the sample is smaller. But still, the direction is interesting.

Router returns: a sad story

We are also collecting routers that students left behind when moving out. The result? Not great: less than 5 % of these devices can even do 5 GHz Wi-Fi – and so they can’t handle gigabit properly.

Of course, if someone owns a good router, they don’t leave it behind. But still, it’s shocking how many people were using outdated hardware: old Fast Ethernet ports, no 5 GHz, weak Wi-Fi chips. No wonder the speeds suffer.

Conclusion

For us that means: more awareness needed! Either many students don’t know what their connection could really do – or maybe they just don’t need much internet at all. Apart from one building in Tübingen (we’re still waiting for the key), we’ve already put up our own posters in all 102 student housing buildings. Let’s see if that helps.