Edge-Core ECS4120-28F, Справочное руководство, Страница: 548 / 938

Chapter 20
| ERPS Commands
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node under maintenance in order to avoid falling into the above mentioned
unrecoverable situation.
Example
Console#erps forced-switch domain r&d west
Console#
erps manual-switch
This command blocks the specified ring port, in the absence of a failure or an erps
forced-switch command.
Syntax
erps manual-switch [ domain ring-name ] { east | west }
ring-name - Name of a specific ERPS ring. (Range: 1-12 characters)
east - East ring port.
west - West ring port.
Command Mode
Privileged Exec
Command Usage
◆
A ring with no request has a logical topology with the traffic channel blocked at
the RPL and unblocked on all other ring links. In this situation, the
erps
manual-switch command triggers protection switching as follows:
a.
If no other higher priority commands exist, the ring node, where a manual
switch command was issued, blocks the traffic channel and R-APS channel
on the ring port to which the command was issued, and unblocks the other
ring port.
b.
If no other higher priority commands exist, the ring node where the
manual switch command was issued transmits R-APS messages over both
ring ports indicating MS. R-APS (MS) message are continuously transmitted
by this ring node while the local MS command is the ring node’s highest
priority command (see
Table 101 on page 547 ). The R-APS (MS) message
informs other ring nodes of the MS command and that the traffic channel is
blocked on one ring port.
c.
If no other higher priority commands exist and assuming the ring node was
in Idle state before the manual switch command was issued, the ring node
flushes its local FDB.
d.
A ring node accepting an R-APS (MS) message, without any local higher
priority requests unblocks any blocked ring port which does not have an SF
condition. This action subsequently unblocks the traffic channel over the
RPL.