Using dnsmasq to resolve all hosts to the same address

Question

I'm running Ubuntu server on a computer used as a wireless AP, but this AP should resolve all DNS requests to an internal IP address rather than actually performing the lookup.

I want to do the same thing that paid public WiFi hotspots do - you can connect but if you attempt to load any websites they show a default page. I've noticed that they do this by resolving all domains to an internal IP address.

I've added these lines to /etc/dnsmasq.conf:

# Add domains which you want to force to an IP address here.
# The example below send any host in double-click.net to a local
# web-server.
address=/com/192.168.2.1
address=/uk/192.168.2.1
address=/org/192.168.2.1
address=/gov/192.168.2.1
address=/net/192.168.2.1
address=/us/192.168.2.1

which works fine for those TLD's, but I'd like to be able to do it with all domains so I can sleep at night.

As the dnsmasq manual says …

… just use # for a wildcard:

address=/#/192.168.2.1

Comments

[Paul Ackerman]

why not just use a captive portal like sputnik or the like? How do you plan to change DNS after they login?

[user]

Trying to achieve this? If you edit your dhcpd and then do iptables -A PREROUTING -s 192.168.0.0/255.255.255.0 -p tcp -j DNAT --to-destination 192.168.2.1

[Matt]

@PaulAckerman I used public WiFi as an example. This AP will never allow real DNS requests to be made. I'll try the iptables thing.

[Pitto]

rtfm indeed but god bless you anyway :D

[Avian00]

Which manual? 'man dnsmasq' gives me a BOAT LOAD of command line options, but almost no information on config file layout.

[jaymmer - Reinstate Monica]

I know this is late, but in case someone finds this useful: all the long options in the dnsmasq man page are valid in config files as well - all you need to do is drop the preceding dashes (and put each option on its own line). Event the argument syntax remains the same.