No Websocket-Connection after forced ISP disconnect/reconnect

I don´t know how it is in other countrys but In Germany, we have Internet-Connections with dynamic IP´s.
If we disconnect from the internet and connect again, we have an other outbound IP as the connection before.
When we don´t disconnect from the internet between 24 hours, we get a forced disconnect from the ISP.
The Result is also an other outbound IP as the connection before.

The websocket-sharp client do not register this disconnect.
After this diconnect, I got a new dynamic IP and the Websocket-Connection between Websocket-Client und Websocket-Server dows not exist anymore, because my Client got a new IP.

If I try this situation locally (Server and Client both have static IP´s), I don´t have this problems.
The Connection is down and after reconnect, the same connection is automatically used again.

I´ve tryed the same with a HTML5 Websocket client.
The result is that the HTML5 Client fired the OnClose event after a few seconds (eventually an internal timeout ?).

Do you have any ideas to resolve this problem?
Or should I take a timer that pings the server every minute to monitor the connection - and if I detect an error I make a new connection from the cient to the server?

No source file or test is named. Start by tracing the websocket-sharp client connection lifecycle and its disconnect or close detection, then reproduce a forced network disconnect and compare it with the HTML5 client's OnClose behavior; completion criteria are not defined beyond detecting the lost connection and determining whether reconnection is expected.