dnmmsd module is responsible for monitoring devices discovered in a managed network. As a result you can see a topology map of a monitored network. The module makes the gathered information about devices available to its clients. The graphic application xdnmm that presents topological maps of networks is one of the module client.

During startup of dnmmsd is run, it creates two child processes. The first one is responsible for sending and receiving ICMP-ECHO packets to monitored devices discovered by dnmmsd daemon and to IP addresses configured by a user. The second one serves SNMP requests sending to monitored devices discovered by dnmmsd daemon.

As next step the Network Information Database is loaded from a file specified as an argument of -i,--db-import option. The operation has one-time character i.e. an import of data will be done when Network Information Database is accepted as empty. In the end dnmmsd begins awaiting for clients' requests and monitoring of network management.