Nagios

Hello,

     I've recently started making a research on Network Management Systems
(NMS) for IP Networks and have a basic doubt that i'd hope someone could
help me out with. As far as I understand some tools are able to not only
monitor but also react to traps and set configurations on your devices. Is
Nagios capable of not only monitoring but also configuring the external
devices it is monitoring? A second doubt would be: is there any plugin that
supports showing the topology map of the network being monitored?

Thanks!