User Manual

C HAPTER 38 | ERPS Commands
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Configuration Guidelines for ERPS
1. Create an ERPS ring: Create a ring using the erps domain command.
The ring name is used as an index in the G.8032 database.
2. Configure the east and west interfaces: Each node on the ring connects
to it through two ring ports. Use the ring-port command to configure
one port connected to the next node in the ring to the east (or
clockwise direction); and then use the ring-port command again to
configure another port facing west in the ring.
3. Configure the RPL owner: Configure one node in the ring as the Ring
Protection Link (RPL) owner using the rpl owner command. When this
switch is configured as the RPL owner, the west ring port is set as being
connected to the RPL. Under normal operations (Idle state), the RPL is
blocked to ensure that a loop cannot form in the ring. If a signal failure
brings down any other link in the ring, the RPL will be unblocked
(Protection state) to ensure proper connectivity among all ring nodes
until the failure is recovered.
4. Configure ERPS timers: Use the guard-timer command to set the timer
is used to prevent ring nodes from receiving outdated R-APS messages,
the holdoff-timer command to filter out intermittent link faults, and the
wtr-timer command to verify that the ring has stabilized before
blocking the RPL after recovery from a signal failure.
5. Configure the ERPS Control VLAN (CVLAN): Use the control-vlan
command to create the VLAN used to pass R-APS ring maintenance
commands. The CVLAN must NOT be configured with an IP address. In
addition, only ring ports may be added to the CVLAN (prior to
configuring the VLAN as a CVLAN). No other ports can be members of
this VLAN (once set as a CVLAN). Also, the ring ports of the CVLAN
must be tagged. Failure to observe these restrictions can result in a
loop in the network.
6. Enable ERPS: Before enabling a ring as described in the next step, first
use the erps command to globally enable ERPS on the switch. If ERPS
has not yet been enabled or has been disabled with the no erps
command, no ERPS rings will work.
7. Enable an ERPS ring: Before an ERPS ring can work, it must be enabled
using the enable command. When configuration is completed and the
ring enabled, R-APS messages will start flowing in the control VLAN,
and normal traffic will begin to flow in the data VLANs. To stop a ring, it
can be disabled on any node using the no enable command.
8. Display ERPS status information: Use the show erps command to
display general ERPS status information or detailed ERPS status
information for a specific ring.