NCache 4.6 - Online Documentation

Blocked Node Communication due to Firewall

Sometimes a cluster can not be formed, or cluster nodes are unable to communicate with each other. It may happen when Server and Cluster ports are blocked by firewall. Following error messages can occur in this case.
Error: "No server available to process request"
Error: "Unable to communicate with server node"
  • If cluster is not formed, make it sure that Server port, at which NCache Service starts and accepts different client connections, is not blocked by firewall. Default value of this port is '9800'. You can change the default value from Alachisoft.NCache.Service.exe.config file.
  • If nodes in a cluster are unable to communicate, please see if your firewall is allowing the Cluster port. Cluster port is a port at which nodes in a cluster communicate. You can change the default value of these ports from NCache Manager. If you have specified a port range in NCache Manager, unblock all ports in range.
  • If NCache Manager is unable to connect with NCache Service, even when it is started, then your system firewall might be blocking Service port. Unblock Service port from system firewall.
See Also