Re: redirect unauthenticated traffic to a registration portal

[Song Du <freewizard@gmail.com>]

just like transparent proxy
assume http://AUTH_PORTAL_IP is where user can type password and become authed.
iptables -t nat -A PREROUTING CONDITIONS_TO_MATCH_AUTHED -j ACCEPT
iptables -t nat -A PREROUTING -p tcp --dport 80 -j DNAT --to AUTH_PORTAL_IP
iptables -t nat -A PREROUTING -j DROP


2005/6/6, Phani Kumar <pkumar@students.iiit.net>:
> Hi,
>    I have implemented a linux router with 4 interfaces.
> 
> eth0 -- outside net
> eth1 --
> eth2 --    diff Internal n/ws
> eth3 --
> 
> Now I had to allow only authenticated traffic to pass through the
> router(i.e through interface eth0).
> I have a list of all authenticated Mac-addresses in a file.
> 
> All unauthenticated traffic (i.e non-authenticated mac-address traffic)
> had to be redirected to default registration site.
> 
> Pls can anyone suggest me how to do above task.
> I am able to allow only authenticated traffic by using
> 
> iptables -t filter -A FORWARD -m --mac-source xx.xx.xx... -i eth0 -j
> ACCEPT
> 
> and so on for all authenticated users
> 
> iptables -t filter -A FORWARD -i eth0 -j DROP
> 
> How do I redirect the unathenticated traffic to a registration portal
> rather than dropping it??
> 
> Phani
> IIIT-Hyd
> 
> 


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