Well, yes you can - although there are really good reasons for two physically separated networks. I am testing it currently withIm not sure but I guess you cant use the same network192.168.0.0/24
for both ceph networks.
Code:
~# grep _network /etc/ceph/ceph.conf
cluster_network = 10.3.16.7/16
public_network = 10.3.16.7/16
...and it seems to work. Again: not recommended. And additionally: keep an eye on corosync, I have that one on different network cable.
Best regards