Brocade 6910 Ethernet Access Switch Configuration Guide (Supporting R2.2.0.0) User Manual
Page 1043
Brocade 6910 Ethernet Access Switch Configuration Guide
987
53-1002651-02
43
Ethernet Ring Protection Switching
•
Down – The interface is not linked up.
•
Unknown – The interface is not in a known state.
•
East Port – Connects to next ring node to the east.
•
RPL Port – If node is connected to the RPL, this shows by which interface.
•
RPL Owner – Configures a ring node to be the Ring Protection Link (RPL) owner.
•
Holdoff Timer – The hold-off timer is used to filter out intermittent link faults. Faults will only be
reported to the ring protection mechanism if this timer expires. (Range: 0-10000 milliseconds,
in steps of 100 milliseconds)
In order to coordinate timing of protection switches at multiple layers, a hold-off timer may be
required. Its purpose is to allow, for example, a server layer protection switch to have a chance
to fix the problem before switching at a client layer.
When a new defect or more severe defect occurs (new Signal Failure), this event will not be
reported immediately to the protection switching mechanism if the provisioned hold-off timer
value is non-zero. Instead, the hold-off timer will be started. When the timer expires, whether a
defect still exists or not, the timer will be checked. If one does exist, that defect will be reported
to the protection switching mechanism. The reported defect need not be the same one that
started the timer.
•
Guard Timer – The guard timer is used to prevent ring nodes from receiving outdated R-APS
messages. During the duration of the guard timer, all received R-APS messages are ignored by
the ring protection control process, giving time for old messages still circulating on the ring to
expire. (Range: 10-2000 milliseconds, in steps of 10 milliseconds)
The guard timer duration should be greater than the maximum expected forwarding delay for
an R-APS message to pass around the ring. A side-effect of the guard timer is that during its
duration, a node will be unaware of new or existing ring requests transmitted from other nodes.
•
WTR Timer – The wait-to-restore timer is used to verify that the ring has stabilized before
blocking the RPL after recovery from a signal failure. (Range: 5-12 minutes)
If the switch goes into ring protection state due to a signal failure, after the failure condition is
cleared, the RPL owner will start the wait-to-restore timer and wait until it expires to verify that
the ring has stabilized before blocking the RPL and returning to the Idle (normal operating)
state.
•
Control VLAN – A dedicated VLAN used for sending and receiving R-APS protocol messages.
(Range: 1-4093)
Configure one control VLAN for each ERPS ring. First create the VLAN to be used as the control
VLAN (see
on page 752), add the ring ports for the east and west
interface as tagged members to this VLAN (see
“Adding Static Members to VLANs”
page 754), and then use this parameter to add it to the ring.
The following restrictions are recommended to avoid creating a loop in the network or other
problems which may occur under some situations:
•
The Control VLAN must not be configured as a Layer 3 interface (with an IP address), a
dynamic VLAN (with GVRP enabled), nor as a private VLAN.
•
In addition, only ring ports may be added to the Control VLAN. No other ports can be
members of this VLAN.
•
Also, the ring ports of the Control VLAN must be tagged.