Hello,
Did the option 'keepalive' '10 120' work for you?
L2TP uses LCP Echo Requests as a keep alive for the L2TP VPN.
The file with these settings is options.xl2tpd located in /var/etc/ directory.
Try modifying the values assigned to the following options:
- lcp-echo-interval
- lcp-echo-failure
Best regards,