Some school networks filter access to the internet to prevent students from accessing inappropriate sites. Many do this by “whitelisting” acceptable sites and filtering out all others. If this is true for your school, when you attempt to open https://codap.concord.org/app or https://sagemodeler.concord.org/app on your school network it will fail all the time. You may need to ask your school’s network administrator to whitelist certain domains. CODAP requires the following domains:

• codap.concord.org
  

Sage modeler requires:

• sagemodeler.concord.org
  

Usually, whitelisting “concord.org” is sufficient to permit access to “codap.concord.org” and “sagemodeler.concord.org”.

To have access to the very popular document sharing feature in CODAP or SageModeler, whitelisting token-service-62822.firebaseapp.com is necessary.

To have access to the online image database within SageModeler, whitelisting pixabay.com (or at least the kinds of urls SageModeler uses to communicate with Pixabay) is needed. To restrict use of Pixabay searches to just those done safely from within SageModeler, additional filters can be applied. All URLs sent or received from pixabay via SageModeler will include /api/ or /get/ as part of the URL.