[Koha] Installation error

[Fabio]

Hi all,

I installed koha in Ubuntu 16.04, but I can not access the site via 
firefox. Error message in firerox: ############################### Hmm. 
We're having trouble finding this site. We can not connect to the server 
in library.ffm.org. If this address is correct, here are other things 
you can try: - Try again later. - Check your network connection. - If 
you are logged in behind a firewall, make sure that Firefox is allowed 
to access the Web. ############################### MySQL (version 
5.7.21) is on and Apache (Apache2 Ubuntu) too. Any tips on what could be 
wrong? Thanks in advanced! Fabio Martins Brazil