title: MySQL ring replication behind NAT
body: <p>I am considering switching from Firebird where I'm using a hand-built replication to MySQL and its integrated replication solution. I have 4 departments with sporadic network connections. Each one has to have its copy of the database, and has to be able to update database, so I decided that using ring replication method (A->B, B->C, C->D, D->A) would be the best (correct me if I'm wrong!).</p>
  
  <p>However, while 3 of the departments have a public connection to the outside world, one is behind NAT and I do not have any chance to forward ports - so basically, I can only connect to outside world, but cannot accept incoming connections. Is there any way to set up ring type replication with this limitation?</p>