Peavey MediaMatrix Nion Hardware Manual page 72

Appendix A - Troubleshooting
Some devices will transmit multicast data in normal operation. In a large network, if many or
all devices on the net do so by coincidence at the same time, a condition similar to a data storm
can occur and have similar consequences for a brief instant.
To put it in audio terms, a network loop is analogous to an audio feedback loop. The screech
one hears in audio feedback is due to continuous positive reinforcement of the signal. A
network loop causes a similar positive reinforcement of the data. Data packets are replicated
and increase in quantity with each hop through a switch until all available network bandwidth
is consumed.
Many Ethernet switches contain some variant of the Spanning Tree Protocol (STP, RSTP or
MSTP) that detects and logically removes loops. Standard STP should not allow a connection
to be made until it is sure that the connection will not cause a loop. MSTP and RSTP can
behave a little differently. If a new connection is made through a port that the protocol
previously considered to be an edge port. (i.e. it cannot be connected to another switch), then
the port will be immediately enabled. If this connection is such that it can create a loop, then a
data storm can occur. Explicitly setting ports within an RSTP/MSTP managed switch to be
edge or bridge ports, per their usage, may alleviate this problem.
Commonly used fault tolerant techniques for CobraNet networks

Intentional creation of a loop, with reliance on STP to remove it, in order to create a spare
connection that will be automatically activated when a link in the network goes down.
68 Version 1.6.4b.1 June 11, 2012