CANOGA PERKINS CanogaOS Configuration Guide - Manual (Page 56)

CanogaOS Configuration Guide
Proprietary & Confidential Canoga Perkins Metro Ethernet Switches Page 56 of 350
9 Configuring ERPS
ERPS technology increases the availability and robustness of Ethernet rings. In the event that a
fiber cut occurs, ERPS converges in less than one second, often in less than 50 milliseconds.
The main idea is described as the following. ERPS operates by declaring an ERPS domain on a
single ring. On that ring domain, one switch, or node, is designated the master node, while all
other nodes are designated as transit nodes. One port of the master node is designated as the
master node’s primary port to the ring; another port is designated as the master node’s secondary
port to the ring. In normal operation, the master node blocks the secondary port for all non-ERPS
traffic belonging to this ERPS domain, thereby avoiding a loop in the ring. Keep-alive messages
are sent by the master node in a pre-set time interval. Transit nodes in the ring domain will
forward the ERPS messages. Once a link failure event occurs, the master node will detect this
either by receiving the link-down message sent by the node adjacent to the failed link or by the
timeout of the keep-alive message. After link failure is detected, master node will open the
secondary port for data traffic to re-route the traffic.
9.1.1 References
The ERPS module is based on the following RFC:
RFC 3619
ERPS is a soft-state protocol. The main requirement is to enable ERPS on desired devices, and
configure the ERPS information correctly for various network topologies.
This section provides ERPS configuration examples for there typical network topologies.
Note: For details on the commands used in the following examples, refer to the ERPS Command
Reference.
9.1.2 Configuring ERPS for a Single-Ring Topology
Configure same ERPS domain and ring at switch 1, switch 2 and switch 3. Switch 1 is
configured as ERPS master node and other two switches are configured as ERPS transit nodes.
Interface agg11, which has two members called eth-0-9 and eth-0-10, is configured as primary
interface at switch 1 and eth-0-13 is configured as secondary interface.
Note:
z
The ports accessing an ERPS ring must be configured as trunk ports, permitting the traffic of
data VLANs to pass through.
z The ports accessing an ERPS ring must be configured as the members of the control VLAN,
allowing the ERPS packets to be sent and received.
z STP on ports accessing ERPS rings must be disabled.
z Only one node can be configured as master node.
z Control VLAN must not be configured as Layer 3 interface.