Category: Technology

2025-12-11 Construction Work in Reutlingen

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We detected several outages today, including a longer one, at Pestalozzistraße 41 in our monitoring system.

While looking for the cause, we found out that there is intensive construction work going on in the building.

At the moment, all switches except one are online. The following rooms are connected to that switch:
Ground floor 8–12, 1st floor 117–121, 2nd floor 217–221, and 3rd floor 317–321.

We do not know whether these rooms are occupied during the renovation. If they are, please contact us immediately!

We will ask the Studierendenwerk what is going on.

Since all of our dormitories in Reutlingen are connected through this building, we hope that our hardware is not being damaged.

Update: A power line was cut and has now been repaired.

2025-11-30 Maintenance Upgrade Hibuka

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At the Hibuka in the French Quarter, we were able to recruit an Erasmus student for our working group for last week.

Many buildings in the quarter currently do not yet have gigabit connections in the rooms. We are using this opportunity to upgrade the local infrastructure.

Wankheimer Täle 1 forms the central uplink of the French Quarter as well as the buildings in Eugenstraße. During the work, there may be temporary internet outages there.

Our team will start on Sunday, 30 November 2025, at around 10 a.m. and will work its way from building to building. Anyone who would like to have a look at our network technology is warmly invited to stop by.
We will update this blog post regularly throughout the day.

Update, Saturday 6 p.m.: We will only start installation work tomorrow at 12 o’clock.

Update Sunday 1 p.m.: we are starting in Wankerheimer Täle 1

Update Sunday 5:20 p.m.: Provenceweg 1 and Landkutschersweg 4+6 are pretty much finished.

There will still be a short outage of the entire buildings when we switch the fiber connection from 1 to 10 gigabit.

Update Sunday 7 p.m.: The switch to 10 gigabit could not take place due to excessive attenuation on the fiber. The outage lasted 1.5 hours, longer than expected, because diagnostics and rollback were necessary.

Update 16.12.2025: Using new fiber patch cables, we will try to optimize the attenuation on our connection between Franz-Viertel and our server room in Fichtenweg this evening. There will be a few very short outages in Franz-Viertel and Eugenstraße.

Addendum to the outage in Albstadt on 2025-06-04

Jonas on

We had an outage in Albstadt for several days on June 4 this year – in connection with a power failure there. So something happened, a lightning strike or something.

2025-06-04 Outage Albstadt

A member from Albstadt brought the switches to our weekly meeting today and we unscrewed them to see what had happened – when we plugged them in, they no longer started up.

Our analysis: A capacitor in the power supply unit has been smashed due to too much current.

Switch 1:

Switch 2, more detailed, also with the part separated from the rest:

 

2025-03-21 big changes on core

Avatar photoHeinrich Griesenbach on

On March 21, 2025, we will finally install our new MikroTik Cloud Core Router – CCR2216.
All important devices in our network have names. Our new core switch from MikroTik is called “Corey McRotik.”

As the central core switch, it connects all our network segments.

Many people don’t realize that we run a real, independent network.
All student dormitories in Geislingen an der Steige, Hohenheim, Nürtingen, Reutlingen, Albstadt, and Sigmaringen are connected to us in Tübingen and meet here at Fichtenweg 5.
(This is also why we cannot simply add dormitories that are connected via DSL, like those in Rottenburg, to our network.)

During the upgrade, all dormitories will go offline one or multiple times for a short period, depending on how we need to switch the fiber optic connections.

We chose Friday during the semester break to minimize disruptions for students and avoid interfering with the Studierendenwerk.

Our homepage is no longer hosted on a server at Fichtenweg—it is now hosted externally.
The main reason for this change was a series of power outages in our server room, which not only took all dormitories offline but also made our homepage unavailable.
We don’t expect frequent power outages, but with this change, we can provide more reliable updates in case of problems.

In short:

No need to worry, no emails, and please do not report the planned outage on Friday at 6:00 PM—we are aware of it.
We will be in the server room, literally holding cables in our hands.
We will update this message once we are finished.
If you still have problems after restarting at least one router, please contact us immediately via the contact form.
We will stay on-site for a few more hours to fix configuration issues or, if necessary, undo changes to keep the internet downtime as short as possible.

If you are interested in large networks, feel free to contact us (contact form: Mitmachen).
No prior knowledge is needed!
This year, we will replace switches in over 100 buildings—it’s manual work, so every helping hand is welcome.

If technology is not your strength, but you still want to help, we would really appreciate it.
As you can see from this not-so-perfect text, we could also use someone who can write better texts, design announcements, or simply organize tasks.

Right now, we are mainly active in Tübingen, but we already have one person in Hohenheim who recently joined to help on-site.
We really appreciate people outside of Tübingen because you can reach locations faster.

For example, you could help someone in a dorm with router issues, check if a construction crew accidentally cut a fiber optic cable, or look in the basement to see if a power outage is causing a network problem. All of this is much more difficult for our volunteer team in Netz-AK to handle from Tübingen.

6:16 pm update: after 4 minutes of downtime we finished. If anything is different for you, contact us!

Heads-Up: Friday, 06/12/2024 – New switch, new luck! 🚀

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Hi everyone,

It’s time! On Friday, December 6, 2024, we’re finally installing the new generation of switches in the dorms on Konrad-Adenauer-Strssße. 🎉

What does this mean for you?
During the installation – about 3 hours – the dorms will be completely offline. No connection, no internet, no streaming, sorry! 🙈

Please don’t contact us during this time or ask how much longer it will take. It’ll take as long as it takes – but we promise to work as fast as we can! 💪

What’s new?
The new MikroTik switches are a test to see if they can replace our old Alcatel devices. Small tests went smoothly, but now it’s time for the real thing. Fingers crossed that everything works as planned! 🤞

Thanks for your patience and understanding – after the update, you’ll be the first to enjoy the new speed! 🖥️⚡

Your volunteers of the Netz-AK 🌐

Update: Saturday, 3:05 am we are back in Fichtenweg and configuring the last minor things. (That were very long three hours 😃 )

Update: Sunday, ~9 pm. we are replacing some modules and hope to connect the dormitories in Konrad-Adenauer-Strasse at 10 Gigabit to Fichtenweg 5.

2024-08-21 Muenzgasse 7

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Muenzgasse 7 has been shown as offline since last night.

So far, no one has contacted us. We are preparing to upgrade the building to Gigabit. (12:00)

3 PM: No power, no internet. We upgraded the hardware. As soon as the power is back on you got gigabit internet.

Why a Router?

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Router: With a router, you can create your own small computer network in your dorm room, where your devices usually go online via Wi-Fi through your router. Your router is connected to a device called a switch, which is typically located in the basement of your dorm. This switch is usually directly connected to us at Fichtenweg 5 in Tübingen via fiber optic cable. From there, the connection goes to the Data Center of the University of Tübingen, and from there to BelWü and beyond. The term Internet is based on the interconnectivity between networks.

To communicate between devices on the Internet, they need to find each other. For this, there are IP addresses, which we can compare to phone numbers for this explanation. We have a limited number of these addresses and can provide each of you with one. Since nowadays you have more than one device that wants to go online at the same time, it would cause problems without a router.

Access Point: An access point is not a router and does not create its own network. An access point is an entry point for a network. The access point needs an IP address to function. We give you exactly one IP address. If you connect an access point in your room, it gets an IP address from us. A smartphone connected to the access point does not go online at first, and you can’t access the access point because they don’t know each other’s addresses. The access point usually does not ask for a new IP address and forgets the assigned one after a while. A device in the Wi-Fi of the access point, such as a smartphone, continuously asks for an IP address and gets one from us after a maximum of two minutes if the access point has no more IP addresses. Then the smartphone can go online. Your laptop, however, will not go online through the access point. Therefore, you need a router.

Range Extender: Range extenders increase the range of a Wi-Fi network and do nothing else. So, you can’t do much with a range extender; at best, it might work like an access point.

Important Note: If you unplug your router and connect a laptop directly to the network socket, please wait 2 minutes before assuming there is an error or doing further diagnostics. The limitation to one IP address per room has a timer of 60 seconds. After 2 minutes, you will definitely have a new IP address from us if your devices are configured correctly.

Konrad-Adenauer-Strasse SoSe 2024

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As announced on January 13, we are now using our standard configuration on Konrad-Adenauer-Strasse, after extending it for an additional month.

The change will prevent access points, repeaters, and incorrectly configured routers from using up too many IP addresses, which can deny other residents access to the internet.

Instructions on how to configure routers can always be found in our tutorials.

Maintenance work announcement Viktor-Renner-Straße

Malte on

On Thursday, April 18, starting around 6:30 PM, we will finally be able to equip our dormitories in Viktor-Renner-Straße with more modern technology.
For the residents, this means they will be able to use gigabit internet in their rooms afterwards.
For us as Netz-AK the upgrade also brings us major advantages in the management of our network. The switches that were previously installed in Viktor-Renner-Straße are the very last to not support various standard features and needed to be configured very differently from the rest of our infrastructure, hindering any automation efforts.
We expect the installation to take about 3 hours, meaning you will probably have unrestricted internet access again from 9:30 PM.

Update 2024-04-23: After we were initially only able to replace the switches at Viktor-Renner-Straße 2 last Thursday, we have completed all maintenance work at 4 today. If you still have problems with your internet, please contact us individually using our contact form! This is the only way we can identify the individual problems and help you effectively, because the sources of error can be very different.

As everywhere else in our network, the maximum number of IP addresses assigned in Viktor-Renner-Straße is now basically limited to 1 per connection. However, you don’t have to buy a new router now if, for example, you have previously operated a WiFi repeater and therefore need several IP addresses. For all such connections that we could identify, we have temporarily relaxed this restriction. Let us know if we missed one.