генерить страницу чем-нить типа Апача.
если Демон будет на другой машине, пусть даже в одной сети с клиентами, то перенаправлять надо через DNAT.
Redirection
There is a specialized case of Destination NAT called redirection: it is a simple convenience which is exactly equivalent to doing DNAT to the address of the incoming interface.
## Send incoming port-80 web traffic to our squid (transparent) proxy
# iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 80 \
-j REDIRECT --to-port 3128
Note that squid needs to be configured to know it's a transparent proxy!
и вообще www.netfilter.org и http://www.netfilter.org/documentation/HOWTO//NAT-HOWTO-6.html прочитай.