Data Replication isn't working for me. Any troubleshooting tips?

• Check if the machines are on the same subnet. ifconfig -a should show the ip address of both the machines to be on the same subnet.

• On Linux/Unix,

ifconfig -a

should show the MULTICAST attribute present for your network interface. Also ensure that the interface is in up and running state. If multicast is not enabled, you can use :

ifconfig <interfacename> multicast

to enable it.
On Windows, open Regedit and look for

HKEY_LOCAL_Machine > SYSTEM > CurrentControlSet > Services > Tcpip > Parameters.

Look for the parameter TrFunctionalMcastAddress and see if the value is set to 0. If its not set to 0, set it to 0.

• In your multi machine setup, look in the server.log file if you have entries that show phases such as ADD_EVENT or MASTER_CHANGE_EVENT. And in the log line above it see if both the instances are present. This could be a symptom of multicast not being enabled or not being on the same subnet.

• Also ensure your /etc/hosts file has your ip mapped to your machine.

• Also see the following entry on basic multicast testing : FaqBasicMulticastTestBetweenMachines

(answer by Shreedhar Ganapathy)