Gitlab Package Update impossible


I’m trying to install Gitlab on my Debian following the instructions here:

Installation is aborted because the package seems to be unknown. When I run “apt-get update” I have the following error:

Err:15 stretch InRelease
Operation timed out after 120000 milliseconds with 0 out of 0 bytes received

I also tried to connect using my Smartphone connection, with the same error. What could be wrong?

The IT were blocking the connection to, connection that I redirected to my smartphone.
But it seems that the connection to as also to be clear to download apt update.

So redirecting booth connection to and seems to solve problems if your are behind a proxy.