captive portal " regular,bypass,deny"

[mohandshamada]

hi this is the problem i face it with zentyal i was using mikrotik router OS but it so bad for networks and i'm now using zentyal but only few things i need "captive portal" to do
i want to make users to authenticate with captive portal and make some users to bypass the captive portal login page
and if i need to block users from accessing the internet i need to make him blocked

second problem i read the documentary and found that if i enabled the transparent mode in " HTTP Proxy"
captive portal doesn't work
and found that i can make it work by making port forwarding so how can i make port forwarding

third problem I installed package " arp on " that prevant " arp posioning , spoofing , DDOS...etc"
and run it .
is it working now or it need another configuration to work