Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 1490)

EPSR Introduction and Configuration
Software Reference for x310 Series Switches
57.8 AlliedWare Plus TM Operating System - Version 5.4.4C C613-50046-01 REV A
Recovery When One Break is Restored
Figure 57-5 on page 57.8 shows a ring with the link between nodes A and B restored. At
this point the ring’s behavior will depend on whether the epsr enhancedrecovery enable
command on page 58.5 has been set.
Figure 57-5: EPSR Ring with One Link Restored
Enhanced Recovery Disabled
With the enhanced recovery feature disabled, the Hello messages will now reach the
remaining ring break; however from a users perspective, the ring will remain as shown in
the split state shown in
Figure 57-4 .
Enhanced Recovery Enabled
With the enhanced recovery feature enabled, switch nodes A and B are able to detect the
restored link, and will place all their ring ports in the forwarding state. Although the ring
will remain in the “failed” state because of the remaining break; communication between
the nodes is restored. The network then operates as shown in
Figure 57-6 .
Data
VL
AN
_2
Data
VLA
N_
1
Contr
ol V
LAN
Master
Node Transit
Node
A
Transit
Node
E
Transit
Node
B
Transit
Node
C
Master Node Hello Message Control VLAN
Transit
Node
D
EPSR Plus.eps
P S
The data VLAN ports are in
the pre-forwarding mode
and still blocked.
Data VLANs