Case Study: The Portal Page Cannot Be Displayed Because DNS Packets from STAs Are Not Permitted in the AC Authentication-Free Rule Profile

Symptom

In a Portal authentication scenario, the Portal authentication page is not displayed after a STA connects to the WLAN. As a result, the STA cannot access the WLAN.

Relevant Alarms and Logs

None

Cause Analysis

The DNS is not bypassed. As a result, the Portal page fails to be redirected and cannot be displayed.

Procedure

1. After the IP address of the Portal page is directly entered in the browser of the STA, the Portal authentication page is displayed.
2. Run the display current-configuration command on the AC to check whether basic configurations related to Portal authentication are correct.
3. On the AP, check whether the Portal URL pushed by the AP is correct.

   <AP> debug portal all
   <AP> terminal debugging
   <AP> terminal monitor

   The command output does not contain HTTP or HTTPS packets that trigger Portal redirection.

4. Run the display wsrv portal free-rule command in the diagnostic view of the AP to check the Portal authentication-free rule on the AP. The command output shows that DNS packets are not permitted.
5. Check whether the authentication-free rule for Portal authentication users is configured on the AC. The command output shows that no rule is configured.

   [AC] display free-rule-template configuration name test
   free-rule-template name test
   Total 0 free-rule(s)

6. Configure the authentication-free rule profile on the AC to permit DNS packets from STAs.

   [AC] free-rule-template name test
   [AC-free-rule-f1] free-rule 10 destination ip x.x.x.x mask 255.255.255.255