Redirect to Host Name Network Rule Conditions
(Snort 3.0 only.)—You can use a network object that contains the fully-qualified host name (FQDN) of the interface that captive portal can use for active authentication requests.
The FQDN must resolve to the IP address of one of the interfaces on a managed device. By using an FQDN, you can assign a certificate for active authentication that the client will recognize, thus avoiding the untrusted certificate warning users get when being redirected to a managed device's IP address.
The certificate can specify one FQDN, a wildcard FQDN, or multiple FQDNs in the Subject Alternate Names (SAN) in the certificate.
If an identity rule requires active authentication for a user, but you do not specify a redirect FQDN, the user is redirected to the captive portal port on the managed device interface to which they are connected.
If you do not supply a Redirect to Host Name FQDN, the HTTP Basic, HTTP Response Page, and NTLM authentication methods redirect the user to the captive portal using the IP address of the interface. However, for HTTP Negotiate, the user is redirected using the fully-qualified DNS name firewall-hostname.directory-server-domain-name . To use HTTP Negotiate without a Redirect to Host Name FQDN, you must also update your DNS server to map this name to the IP addresses of all inside interfaces where you are requiring active authentication. Otherwise, the redirection cannot complete, and users cannot authenticate.
We recommend that you always provide a Redirect to Host Name FQDN to ensure consistent behavior regardless of authentication method.