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Introduction to OAM Link Fault Management (LFM)

SUMMARY This section describes the Operation, Administration, and Management (OAM) of link fault management (LFM).

Configuring Ethernet 802.3ah OAM

The IEEE 802.3ah standard for Operation, Administration, and Management (OAM) provides a specification for Ethernet in the first mile (EFM) connectivity. EFM defines how Ethernet can be transmitted over new media types using new Ethernet physical layer (PHY) interfaces. You can configure IEEE 802.3ah OAM on Ethernet point-to-point direct links or links across Ethernet repeaters. The IEEE 802.3ah OAM standard meets the requirement for OAM capabilities as Ethernet moves from being solely an enterprise technology to being a WAN and access technology, as well as being backward-compatible with existing Ethernet technology.

For Ethernet interfaces capable of running at 100 Mbps or faster, the IEEE 802.3ah OAM standard is supported on numerous Juniper Networks routers and switches. This topic describes configuration support for IEEE 802.3ah OAM features on routers.

Beginning in Junos OS Release 12.1, PTX Series routers support the following IEEE 802.3ah OAM features at the physical interface level:

  • Discovery and link monitoring

  • Fault signaling and detection

  • Periodic packet management (PPM) processing

  • Action profile support

  • Graceful Routing Engine switchover (GRES)

To configure 802.3ah OAM support for Ethernet interfaces, include the oam statement at the [edit protocols] hierarchy level:

You can configure threshold values for fault events that trigger the sending of link event TLVs when the values exceed the threshold. To set threshold values for fault events on an interface, include the event-thresholds statement at the [edit protocols oam ethernet link-fault-management interface] hierarchy level.

You can also configure OAM threshold values within an action profile and apply the action profile to multiple interfaces. To create an action profile, include the action-profile statement at the [edit protocols oam ethernet link-fault-management] hierarchy level.

You can configure Ethernet OAM either on an aggregate interface or on each of its member links. However, we recommend that you configure Ethernet OAM on the aggregate interface, and this will internally enable Ethernet OAM on the member links.

To view OAM statistics, use the show oam ethernet link-fault-management operational mode command. To clear OAM statistics, use the clear oam ethernet link-fault-management statistics operational mode command. To clear link-fault management state information and restart the link discovery process on Ethernet interfaces, use the clear oam ethernet link-fault-management state operational mode command. For more information about these commands, see the CLI Explorer.

To enable IEEE 802.3ah OAM support, include the interface statement at the [edit protocols oam ethernet link-fault-management] hierarchy level:

When you enable IEEE 802.3ah OAM on a physical interface, the discovery process is automatically triggered.

Change History Table

Feature support is determined by the platform and release you are using. Use Feature Explorer to determine if a feature is supported on your platform.

Starting in Junos OS Release 17.3R1, the Ethernet link fault management daemon (lfmd) runs on the backup Routing Engine as well when graceful Routing Engine switchover (GRES) is configured.