The NAS Manager replication and data migration features use the NDMP service on the NAS server. The NDMP service is usually accessed via the IP address of the EVS which hosts the file system, this access usually happens through a Gigabit Ethernet port. In some cases, the IP address is within a private subnetwork and is not accessible from the NAS Manager. When this is the case, the ndmp-management-ports-set command can be used to request that the NAS Manager access goes through the management ports and is then relayed to the NDMP service.
The ndmp-management-ports-set command takes two parameters which are the TCP ports. One is used to accept the incoming connection on the management port and one is used to pass the requests to the NDMP code. These must be ports that are not in use by any other service. In particular, these ports must not be the standard NDMP service port. The port numbers 10001 and 10002 usually work and, being next to the standard NDMP port 10000, can be useful in identifying the port usage.
Having set up the NDMP management ports this way, all NAS Manager replication and data migration NDMP accesses will be routed via the management port. Note that the actual data transfer connections involved are between the NAS server EVSs and do not run over the management connections. In particular, a replication between two NAS servers passes the data over a TCP connection between EVS IP addresses through the Gigabit Ethernet ports. Therefore, the two EVSs must have IP addresses that can communicate with each other.