Barox L Series, Operating Instructions Manual, Page: 15 / 69

barox Kommunikation 15
3.9 Ring Configuration
To guarantee redundancy within the network, it is crucial to set up a ring topology. To ensure
that the network is not overloaded by a broadcast storm, a protection mechanism is required.
RSTP (Rapid Spanning Tree Protocol) is one of the fundamental proto cols used in an Ethernet
network. It ensures that no network loops are created within individual network segments. Unlike
an IP packet, an Ethernet frame does not have a maximum Time to Live (TTL) and, therefore,
may potentially go around in circles for an indefinite period of time. This, in turn, could overload
the network and, in the worst case, bring the network to a standstill.
How the Rapid Spanning Tree Protocol works is explained in detail in Wikipedia.
https://de.wikipedia.org/wiki/Spanning_Tree_Protocol
3.9.1. Ring Master
In a ring topology, one switch must be defined as the master which then assumes the task of
monitoring the ring. In the event that a connection is interrupted, this master then notifies all
the other switches in the ring so that the alternative connection can be activated. The switch
with Priority 0 is the ring master.
The RSTP protocol is designed to automatically make the switch with the lowest MAC address
the ring master, if no ring master has been defined.
The desired protocol version must be selected in the “Spanning Tree/Bridge Settings” menu.
RSTP is supported by all switch manufacturers - making it compatible with third-party
manufacturers.
The switch factory default is set to “Bridge Priority” 32768. If the switch is to act as master,
the Bridge Priority must be set to “0”. All the other values can be left as they are.
Ring master has Priority “0”.