Can´t open CRUST after installation

Dear friends, I m walking my first steps with univention community version. After tests of some software I installed CRUST. After installation and klick onto the link in the portal a subdomain was loaded in the browser: crust.hostname.domain but nothing happened. All other software bevore was loaded with hostname.domain/appname/
I tried some different adresses to open CRUST. https and http. with crust.ipaddress and ipaddress/crust/ and so forth.
I m new to this technology and I would be pleased if anyone can help on that issue.
For shure it is quite a simple click or bit here or there. Like often in IT. :wink:

So thank you for taking a look to this topic.

Have a nice evening.


I found out, that with localhost:9201 you should come to the login screen. In the header this request is forwarded to localhost:9201/auth/login but there the system shows “network error”.

I made a complete new univention instance and downloaded crust and installed it like all other software on the other systems. But it doesn´t work.

Please Univention Tesm, have a look on that. From my viewpoint this system is not ready to deploy.




Hi Thorsten,

I am not familiar with the installation of CRUST. But there is a small problem with the specific installation type if the network is in the range 172.[17-31].0.0/16
The result can be that apps work and others do not. As you report.
Do you have a network address in that range?

Kind regards

Hi Stefan,
thank you for this fact. My network in use is 192.168.2xx.x/24. But I think there is the docker network. I must have a look.
The docker compose network is 172.16.1.x/16.
The docker default opts bip is 172.17.42.x/16.

Did you mean that?

Kind regards

Hi Thorsten.

Yes, that’s what I mean. Then that’s not what’s causing your problem.

Kind regards

Thank you Stefan for your viewpoint on that issue. :hugs::+1:

Hello @franzx,

just a guess, your browser on your client needs to be able to resolve the hostnames in your UCS domain. Your client should have the UCS name server in his name resolution list. Crust needs several subdomains. Can you resolve the hostname crust.hostname.domain from your client?

And yes, your observation is right that most apps come with https://fqdn/appid. For Crust the requirements are different. The app creates several hostnames and an appropriate SSL certificate.

Best regards,

Hello @franzx ,

you should first check Nico’s comment.
The three subdomains are crust.hostname.domain, api.crust.hostname.domain and didmos2-auth.hostname.domain. If you’re not using the UCS DNS by default, you must configure your DNS manually to be able to resolve these names to the UCS server.

The crust.hostname.domain one is used to access the app, but the other services must be available, so that communication between the services is possible.

In addition, your browser must be configured to trust the certificates generated by UCS. If you have not yet whitelisted the UCS certificate authority, you might have to accept exceptions for all certificates, so that for example crust.hostname.domain is able to talk to api.crust.hostname.domain via your browser.

Best regards,