C&CZ

Technical update for mail‑domain DNS administrators What and why we are doing this With the new setup we are renaming our mail‑component servers so that their names reflect the function they perform in the mail chain. This change has no impact on end users, but it makes troubleshooting and future feature implementation easier because we can immediately identify the machine involved. First step We have renamed mx3 to inboundmx3. Because this is essentially only a DNS change, we have also updated all MX records we manage. Domains for which we provide mail but do not control the DNS must be updated by their own administrators. ...

For a long time, at least since before Covid-19, we have hosted a local jitsi meet installation. The installation was becoming a bit old and stuffy, so time for a new version and a new name. Meet is our new jitsi install for general use. Jitsi Test is our test jitsi install, when we test new features here, so can you. The *old jitsi will be retired soon, so please go try the new one. ...

Enhanced Email Security We are pleased to announce we have completed the first step in the update to our email system. This will improve the security and reliability of your mail handling. As part of this upgrade, we have introduced new software at the start of our email flow (on the inbound MX servers). This advanced system now evaluates incoming emails to determine if they are legitimate. If an email fails to meet the required standards or appears very suspicious, it will be blocked at the entry point, in accordance with RFC guidelines for mail transport. This is a crucial first step toward creating a safer and more secure email environment for everyone. ...

At the start of this year we installed a high-performance server (512 GB memory, two high-end GPUs). This machine now hosts local large-language models LLMs, meaning the AI runs entirely on‑premise and your data never leaves our network. What you can do today Access the web UI at chat.science.ru.nl. Log in with your Science RU username (e.g., jdoe, not jdoe@science.ru.nl). The service is powered by Ollama and Open WebUI, providing a clean, responsive chat interface. Early tests show reliable speech‑to‑text (including Dutch) and the ability to review source code. A user experience that feels very close to the larger commercial models, even though we are currently using open‑source models a few generations older. Current status - experimental We don’t know how many concurrent users the system can support and how much persistent storage will be required. No automated backups are in place; please treat the data you store there as temporary. Uptime is not guaranteed. The service may need to be restarted or the server rebooted when we apply configuration changes or updates. The setup will evolve as we gather feedback, so your input is valuable. Which models are available? Browse the full catalog on ollama.com/search. At the moment we run two modes: gpt‑oss and deepseek-r1 , but others can be added on request. We ran deepseek-r1:671b, but this model is too large for the machine we have. ...

C&CZ was the first to implement e-mail (@sci.kun.nl) at the KUN (Katholieke Universiteit Nijmegen), some 35 years ago. Some configurations we have used since then have not kept up with the changing landscape of e-mail implementations worldwide. In Dutch there’s a saying for this: “De wet van de remmende voorsprong”. One of the major things that have changed over time is dealing with SPAM. For instance, there are now protocols that major e-mail players require and therefore became the de facto standard for email communication. ...

A new, for now experimental, feature is live on DIY, where you can “order” services directly by clicking the + on the right side. Ordering a product. This includes: Accounts: temporary logins, new groups, or guest accounts. Storage: new volumes or cloud endpoints on volumes. Email: create new aliases and mailman lists. Contact us: send an email to the helpdesk. Some services are directly provisioned, for others we still send an email to helpdesk@science.ru.nl where we need to implement the request manually. ...

Some websites under science.ru.nl may be inaccessible Several users have reported that they can no longer access websites such as http://example.science.ru.nl. Browsers block these connections because the parent domain ru.nl now requires HTTPS, while some websites, often served directly from devices or sensors, do not support encrypted connections. We are working on a general solution and will update this article once it becomes available. Background: HTTP Strict Transport Security (HSTS) Modern browsers enforce HTTP Strict Transport Security (HSTS) to prevent unencrypted HTTP access. Domains can opt in by being listed on hstspreload.org. Once listed, all subdomains must use HTTPS, and browsers will block HTTP entirely. ...

For years now Gitlab has bundled Mattermost as an integrated component for online chats, however this situation is changing, and Mattermost has announced that it is dropping support for single-sign-on (SSO). This is turn makes the integration with Gitlab unusable, thus Gitlab is now pondering dropping support altogether. This is unfortunate timing as we are working on tighter integration between science groups and Mattermost channels. Provisional Plan So what are we going to do about this? For chat, we have been looking at Zulip for a while now. This a stand alone, 100% open source chat server that works just like Mattermost. It’s supports OpenID, so we can hook up to diy for SSO. ...

Over the years we’ve had some requests to run an Overleaf instance for science users. To integrate this well in our environment we would need the enterprise version, which costs about € 8,- per user per month. This is prohibitive expensive for us to run, because we would need to pay for all science users, so we will not be pursuing setting up Overleaf any further in the science domain. There are alternatives for this setup, they may or may not work for your use case: ...

The latest version of Matlab, R2025b, is available. The software and license codes are directly available for Science accounts and can be requested by other entitled users by sending mail to the helpdesk. The software can also be found on the install-share. All C&CZ-managed Linux machines have this version installed, the older version (/opt/matlab-R2025a/bin/matlab) will be available temporarily. The C&CZ-managed Windows machines will not receive a new version during the semester to prevent problems with version dependencies in current lectures. ...