parece que a solução é ter 2 verificações: 1 para os processos e 1 para garantir que o host do gateway seja acessível
check process vpn-network with pidfile /var/run/vpn-network.pid
start program = "/etc/init.d/openvpn start vpn-network.com"
stop program = "/etc/init.d/openvpn stop vpn-network.com"
check host tap0 with address 1.1.1.1
start program = "/etc/init.d/openvpn start vpn-network.com"
stop program = "/etc/init.d/openvpn stop vpn-network.com"
if failed
icmp type echo count 5 with timeout 15 seconds
then restart ¶
fonte: link