Westermo RedFox Series - Manual (Page 320)

Westermo OS Management Guide
Version 4.17.0-0
Chapter 15
FRNT Ring Coupling and
Multi-Link Dual Homing
This chapter describes WeOS FRNT Ring Coupling and Multi-Link Dual Homing,
two similar layer-2 (switching) fail-over functions.
FRNT Ring Coupling enables bridging of two or more FRNT rings via multiple
layer-2 uplinks. Only one uplink is active at a time, while others are hot stand-by
backups, providing redundancy and loop-free connectivity.
Multi-Link Dual-Homing (or simply ”Dual-Homing”) lets you connect a WeOS switch
to a layer-2 topology via multiple uplinks. Optimal fail-over performance is achieved
when connecting the dual-homing switch uplinks to a single FRNT ring, or to two
adjacent FRNT rings (connected with Ring Coupling), but Dual-Homing can also
be used in other layer-2 topologies.
Both FRNT Ring Coupling and Multi-Link Dual-Homing provide fine-grained control
of which uplink is to be preferred as active. By default, the link with highest
speed/duplex mode is elected. To avoid shifting between active uplinks when a
new uplink becomes available, a feature referred to as sticky uplink is provided.
Enabling sticky uplink gives ”zero” fail-over time on link-up and mitigates possible
problems with flapping links.
Section 15.1 presents further information on FRNT Ring Coupling and the Multi-
Link Dual-Homing functionality. Web and CLI support for these features are cov-
ered in
sections 15.2 and 15.3 respectively.
320 ➞ 2015 Westermo Teleindustri AB