Partially. Telekom keeps up the line for months at a time. I guess that is due to telephony being done via VoIP, and they don't want to interrupt your late night calls.
Others, even Congstar (which is a cheap telekom brand), do 24h disconnects with a new v4 address, and no v6 at all.
The DSL I use gives me a fixed v4 and v6 range, but still needs to do the daily disconnects.
Our TV started to complain that the Wifi module was unplugged (which apparently is on the main board). Problem: This happened regularly with a dialog box. 'Solution': Put a Wifi dongle in the USB port.
Others, even Congstar (which is a cheap telekom brand), do 24h disconnects with a new v4 address, and no v6 at all.
The DSL I use gives me a fixed v4 and v6 range, but still needs to do the daily disconnects.