This problem may be specific to some installations only and can spread to multiple locations.

HOWEVER, two common ISSUES occurs which are described as follow: - 

1.An External DNS is configured in the specific System. If a ‘Drop’ firewall rule is applied, Cyberoam will block all traffic, including DNS requests. Hence, Captive Portal won’t be displayed.

This can resolved by either of the following SOLUTIONS:

• We should Configure Cyberoam IP address as the DNS in the USER machines.
• We should CREATE a firewall rule which accepts DNS traffic and places it above the ‘Drop’ rule.

2.Captive Portal is not displayed for Clientless Users. This happens because trusted users don’t need any authentication on Cyberoam to access Internet. Hence, Captive Portal is not displayed to clientless users.

This problem may be specific to some installations only and can spread to multiple locations.

However, two common issues occurs which are described as follow: - 

1.An External DNS is configured in the specific System. If a ‘Drop’ firewall rule is applied, Cyberoam will block all traffic, including DNS requests. Hence, Captive Portal won’t be displayed.

This can resolved by either of the following solutions:

2.Captive Portal is not displayed for Clientless Users. This happens because trusted users don’t need any authentication on Cyberoam to access Internet. Hence, Captive Portal is not displayed to clientless users.