  The amount of connected devices in the industrial environment is growing
continuously, due to the ongoing demands of new features like predictive
maintenance. New business models require more data, collected by IIoT edge node
sensors based on inexpensive and low performance Microcontroller Units (MCUs).
A negative side effect of this rise of interconnections is the increased attack
surface, enabled by a larger network with more network services. Attaching
badly documented and cheap devices to industrial networks often without
permission of the administrator even further increases the security risk. A
decent method to monitor the network and detect "unwanted" devices is network
scanning. Typically, this scanning procedure is executed by a computer or
server in each sub-network. In this paper, we introduce network scanning and
mapping as a building block to scan directly from the Industrial Internet of
Things (IIoT) edge node devices. This module scans the network in a
pseudo-random periodic manner to discover devices and detect changes in the
network structure. Furthermore, we validate our approach in an industrial
testbed to show the feasibility of this approach.
