Required only when the VPN server is acting as a VPN client (a calling router) in a site-to-site VPN connection. If all traffic from the VPN server is allowed to reach TCP port 1723, network attacks can emanate from sources on the Internet using this port. Administrators should only use this filter in conjunction with the PPTP filters that are also configured on the VPN server.
Are you so used to your data traveling over Wi-Fi that you've stopped worrying about the security of that data—and about who else might be spying on it, or even stealing it for nefarious purposes? If so, you are—sadly—in the majority, and you ought to consider using a viritual private network, or VPN. In fact, when PCMag conducted a survey on VPN usage, we found that a dismal 71 percent of the 1,000 respondents had never used a VPN. Even among those who support net neutrality—who you might think would tend to be well informed on technology and privacy issues—only 45 percent had used a VPN.