Redrects to internal ip ip based on a domain name

[louis-m]

guac is a proxy (much like squid)
you simply point your browser at guac and you are confronted with a logon page. depending on how you have configured the mappings, depends on what you are confronted with.
to point your browser at gauc from external, you will need to create a A record or use your public ip and open up either 80 or 443 and point it to the guac server.
alternatively, you can use squid and map to guac.