A YugabyteDB universe is comprised of exactly one primary cluster and zero or more read replica clusters.
In YCQL we can display the IP addresses of the nodes in the Universe by querying two system tables.
SELECT rpc_address FROM system.local; -- This is the node I am logged into
SELECT rpc_address FROM system.peers; -- These are the other nodes in the Universe
Example:
cassandra@ycqlsh> SELECT rpc_address FROM system.local; -- This is the node I am logged into
rpc_address
----------------
172.164.59.169
(1 rows)
cassandra@ycqlsh> SELECT rpc_address FROM system.peers; -- These are the other nodes in the Universe
rpc_address
----------------
172.164.29.222
172.164.42.157
(2 rows)
In the example, my Universe includes three nodes having the IP addresses 172.164.59.169, 172.164.29.222 and 172.164.42.157.
Have Fun!