Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 1498)

EPSR Introduction and Configuration
Software Reference for x310 Series Switches
57.16 AlliedWare Plus TM Operating System - Version 5.4.4C C613-50046-01 REV A
Interconnected Rings
This example shows an EPSR configuration where two rings share a common segment.
This configuration will operate as two independent rings, providing that there is no data
VLAN sharing between the two rings. If a break occurs in either ring then, each ring will
implement its own independent recovery procedures. If a break occurs in the common
segment, then each Master node will unblock its secondary port using the normal fault
recovery procedure.
Where data VLANS are shared between the rings a fault condition know as “SuperLoop”
can occur. The next section deals with superloops and how to manage them.
Figure 57-9: Interconnected EPSR Rings with No Data VLAN Sharing
EPSR_No-SLoop.eps
Transit
Node
Transit
Node
Transit
Node
Transit
Node
Primary
Port
Secondary
Port
Transit
Node
Master
Node
Master
Node
Transit
Node
Blocked
Blocked
Data VLAN
Control VLAN
Data VLAN
Control VLAN
Primary
Port
Secondary
Port
Control VLAN (Ring One)
Data VLAN (Ring One)
Ring One
Ring Two
Control VLAN (Ring Two)
Data VLAN (Ring Two)