Require network/system logs on Win 8.1 phone. Where are they?

[Windows Central Question]

Require network/system logs on Win 8.1 phone.

I am troubleshooting a Windows 8.1 Lumia 630 phone remotely and need to provide instructions on where network logs can be found.
The issue we suspect is a DNS related problem.

How can we enable debugging or generate logs (the problem app itself does not have any functionality for this)
Where can we find these logs?

Thanks!