Alternatives to using a VPN There are alternatives to using a VPN that you might want to consider. These alternatives provide a simpler way to connect your instance to the resources in the ServiceNow data centers and provide better encryption. Additionally, you can avoid any issues that VPN downtime might cause, such as making your instance unavailable to users if there is an issue with the VPN tunnel. Single sign-on and MID server Consider using a combination of Single Sign-On (SSO) for authentication and the MID Server for user data synchronization, rather than using a VPN to connect your LDAP server to your instance. For integrations other than LDAP, consider using certificate-based encryption. Starting with the Eureka release, you can use: The Okta for single sign-on (see OKTA SSO integration) for more information. The LDAP listener on a MID server to synchronize your user table in near real time. The advantage of this approach is that there are no firewall holes, routes, VPN tunnels, or other special network settings to configure and maintain. The SSO/MID-Server solution is the most flexible, secure and cost-effective method to achieve the complete LDAP integration. LDAP over SSL Another alternative to using a VPN tunnel is to configure LDAP Over SSL (LDAPS) directly over the Internet. You can configure a read-only domain controller and lock the instance down in your DMZ using only the instance's source addresses and the destination ports of your choice. Since the ports for LDAP are configurable in your instance, you can perform a port address translation (PAT) if desired. With LDAPS, you control the certificate that is uploaded over an encrypted channel to the instance, (see Upload a certificate to an instance). The packets cannot be encrypted or decrypted without the certificate. The advantage of this approach is that it provides a stronger encryption and decryption mechanism. A VPN can only encrypt and decrypt the traffic between the two peers sitting on the Internet with a coordinated pre-shared key, similar to a password. LDAPS provides a longer encrypted path, end-to-end, at the application layer and with a certificate that is far more complicated than a pre-shared key that the IPSec tunnel uses.