DevSuite installer cannot download stack software form external links because it uses nodejs request module without proxy settings:
CDK also requires proxy to be configured to have vagrant up working after installation, which could affect CDK Server Adapter Implementation.

To make DevStudio Installer working behind proxy there should be variable HTTPS_PROXY in user environment which sets up URL to proxy server. URL examples for none auth proxy:

• http(s)://servername.com:3128
• http(s)://192.168.0.47:3128

For auth proxy:

• http(s)://username:password@servername.com:3128
• http(s)://username:password@192.168.0.47:3128

If you use email as username then replace @ with %40:

• http(s)://username%40server.com:password@servername.com:3128
• http(s)://username%40server.com:password@192.168.0.47:3128

Additional details are here https://github.com/request/request#controlling-proxy-behaviour-using-environment-variables.