I just registered to add how I did it with my D-Link DHP-1565
curl -v --max-time 10 --connect-timeout 1 -u admin:pswd http://192.168.0.1/reboot.cgi -d "html_response_page=count_down.asp&html_response_return_page=tools_system.asp&html_response_message=The Reboot running&result_timer=50&action=reboot" > /dev/null
I hope it helps on other routers too!!