Fault Message And Recovery - Physical Link - Allied Telesis SwitchBlade x3100 Series Manual

Introduction
= Physical Link
= Control VLAN (1200)
= Data VLAN (600)
UP
10.1
600
10.2
DOWN
EPSR_UCP_Interop

4.8.4.1 Fault Message and Recovery - Physical Link

Assume a fault occurs on link 2. The EPSR protocol reacts and takes steps to change the topology so that no
node is isolated and no new loops are formed. The UPC protocol makes sure that the direction of the ports
(upstream, downstream) are set correctly.
On node C, the UCP protocol sends the Upstream Port Topology Change (4.8.2.2) message for the UFO
VLAN. This message is received and forwarded to the next node until the node that receives the message is the
upstream node (A). Therefore, nodes D and A would receive the message.
4-178
Software Reference for SwitchBlade x3100 Series Switches (Layer Two Switching)
10.0
DOWN
A
1200
1
A D = Devices
1200
1
4
Master
PP Node
2
1200
C
UP
FIGURE 4-23
Primary
Upstream
Interface
DOWN
600
4
1200
= Links
SP
3
600
DOWN
EPSR Topology with UCP
UCP with EPSR/RSTP
Upstream Network
SBx900
Secondary
Upstream
Interface
UP
11.2
600
10.1
DOWN
= data VLAN is blocked
over Physical Link 3
UPC is part of VLAN
messaging and so it
is blocked