xdnmm application is Network Management Map (xdnmm)
and it is a part of Network Manager.
It's a graphic client of dnmmsd daemon that
services Netowrk Management Map,
i.e. it polls devices in managed networks using SNMP protocol and ICMP (ping).
The client is the comfortable interface and it delivers a visualization and
makes commands on objects of Network Information Database that is wholly
managed by dnmmsd.