Cassandra multidatacenter configuration with 1 external ip I'm trying to setup a multi-datacenter Cassandra cluster.
The problem is that my datacenters have only 1 external IP (wan IP), I can setup port forwarding on the data centers switchs to access each node from the outside world using a different port, but I don't know how to setup the cassandra.yaml file properly.

Is there a way to setup a multidatacenter cassandra cluster in this scenario?.

Thanks in advance!
You can try to make each node unique for some of the ports, but this isn't really a good path to go down. Cassandra nodes need to see each other on the ports listed here for the best setup: http://www.datastax.com/documentation/cassandra/1.2/index.html#cassandra/security/secureFireWall_r.html

One option that I have seen work well is a host VPN like Openswan: https://www.openswan.org/projects/openswan/