Add servers to the Cluster

Couchbase Server
1

Hello,
I want to add new servers to My Cluster Couch base server 3.0.3 64 bit, on Ubuntu 14.04 , 64 bit.
I have Public IP and local IP for each server. Every server can ping the other by both local and public IPs.
Should I mention the local IP when adding new servers?
The already existing server is configured on its public IP.

Thanks,
W

2

at the end , I used private Ips instead of public.