There are several enterprise grade tools and hardware is available to evaluate your network performance.This will give you detailed statistics of your network performance with accurate and detailed report. Spirent and Ixia are really good to achieve the same.
However,If you are not concerned about detailed report and 100% accuracy then Iperf tool also can be used to do the same trick.
You can install Iperf Server on your database server#1 and client on the database server #2. Then try to push/pull the data between the servers using iperf tool.
It is a very well documented tool and you can switch between UDP and TCP protocols.I have also forked Iperf for SCTP protocol for my own testing.
Server: iperf3 -s
The server will be by default listening to 5201 for incoming connections and binded to the default network interface.
Client : iperf3 -c "Insert your DB #1 IP" -t 100
Let me know how does it go.
As far as the latency is concerned,You can use hping3 for measuring the latency and for a detailed report.