ASUS RT-AC3200 VPN Server

[Howi]

Looking at the system log, I see, that a certain range of IP-addresses is continuously trying to talk to the vpnserver; port numbers seem to be arbitrary; In my case : 185.200.118.xxx, where xxx is varying.
Looks like this :

7 22:53:10 vpnserver1[534]: 185.200.118.84:33961 TLS: Initial packet from [AF_INET]185.200.118.84:33961 (via [AF_INET]51.174.32.86%eth0), sid=12121212 12121212
Jan 7 22:54:10 vpnserver1[534]: 185.200.118.84:33961 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
Jan 7 22:54:10 vpnserver1[534]: 185.200.118.84:33961 TLS Error: TLS handshake failed
Jan 7 22:54:10 vpnserver1[534]: 185.200.118.84:33961 SIGUSR1[soft,tls-error] received, client-instance restarting
Jan 8 10:36:19 vpnserver1[534]: 185.200.118.89:52451 TLS: Initial packet from [AF_INET]185.200.118.89:52451 (via [AF_INET]51.174.32.86%eth0), sid=12121212 12121212
Jan 8 10:37:19 vpnserver1[534]: 185.200.118.89:52451 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
Jan 8 10:37:19 vpnserver1[534]: 185.200.118.89:52451 TLS Error: TLS handshake failed
Jan 8 10:37:19 vpnserver1[534]: 185.200.118.89:52451 SIGUSR1[soft,tls-error] received, client-instance restarting

Can I block a range of IP-addresses completely ?