Routers - Juniper ACX1000 Configuration Manual

ACX Series Universal Access Router Configuration Guide
Understanding Ethernet OAM Link Fault Management for ACX Series Routers
1112
Understanding and Configuring the Unified Forwarding Table on page 1169
Interpreting the Enterprise-Specific Service OAM MIB on page 1171
The Juniper Networks Junos operating system (Junos OS) for Juniper Networks ACX
Series routers allows the Ethernet interfaces on these routers to support the IEEE 802.3ah
standard for the Operation, Administration, and Maintenance (OAM) of Ethernet in access
networks. The standard defines OAM link fault management (LFM). You can configure
IEEE 802.3ah OAM LFM on point-to-point Ethernet links that are connected either directly
or through Ethernet repeaters. The IEEE 802.3ah standard meets the requirement for
OAM capabilities even as Ethernet moves from being solely an enterprise technology to
a WAN and access technology, and the standard remains backward compatible with
the existing Ethernet technology.
Ethernet OAM provides tools that network management software and network managers
can use to determine how a network of Ethernet links is functioning. Ethernet OAM should:
Rely only on the media access control (MAC) address or virtual LAN identifier for
troubleshooting.
Work independently of the actual Ethernet transport and function over physical Ethernet
ports or a virtual service such as a pseudowire.
Isolate faults over a flat (or single-operator) network architecture or nested or
hierarchical (or multiprovider) networks.
The following OAM LFM features are supported on ACX Series routers:
Discovery and Link Monitoring
The discovery process is triggered automatically when OAM is enabled on the interface.
The discovery process permits Ethernet interfaces to discover and monitor the peer
on the link if it also supports the IEEE 802.3ah standard. You can specify the discovery
mode used for IEEE 802.3ah OAM support. In active mode, the interface discovers and
monitors the peer on the link if the peer also supports IEEE 802.3ah OAM functionality.
In passive mode, the peer initiates the discovery process. After the discovery process
has been initiated, both sides participate in the process. The router performs link
monitoring by sending periodic OAM protocol data units (PDUs) to advertise OAM
mode, configuration, and capabilities.
You can specify the number of OAM PDUs that an interface can skip before the link
between peers is considered down.
Remote Fault Detection
Remote fault detection uses flags and events. Flags are used to convey the following:
Link Fault means a loss of signal
Dying Gasp means an unrecoverable condition such as a power failure. In this
condition, the local peer informs the remote peer about the failure state. When the
remote peer receives a dying-gasp PDU, it takes an action corresponding to the
action profile configured with the link-adjacency-loss event.
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