[CentOS] centos 7 database access only possible trough localhost and not IP

Hi there and hello to everybody,



  I am all new to centos but I have good experience working with ubuntu and suse.
     We are moving a an elderly SuSe box to a virtual machine running centos 7.
     Now I experience the following problem.
     I can only access postgres using localhost as host. If I use the IP address
     (even 127.0.0.1).
     I found a similar problem when accessing the host using http. There I found out
     (after lots of hair pulling) that I have to set a value using setsebool.
     So I assume, that I have a similar problem here.
     I would be grateful, if somebody could point me in the right direction ..
     thanks
  robert