During protal authentication, the portal authentication page cannot be triggered when accessing the HTTP/https webpage

During protal authentication, the portal authentication page cannot be triggered when accessing the HTTP/https webpage， but the portal authentication page can be triggered by entering the IP address in the browser.

When entering the URL, the NDS address will be resolved first, and after the correct IP address is resolved, the portal authentication will be triggered. In order to complete the address resolution, you need to allow access to the DNS address. There are two solutions:

1. portal free-rule 0 destination ip xxxx  //DNS ip address

2. # Configure destination-based portal-free rules 1 and 2 to allow portal users to access the DNS service without authentication.

[AC] portal free-rule 1 destination ip any udp 53

[AC] portal free-rule 2 destination ip any tcp 53