Table of Contents
Advertisement
Related Topics
Guidelines for Configuring 802.3ah OAM Link-Fault Management
Copyright © 2010, Juniper Networks, Inc.
a redundant member, you can use the link monitor functionality to trigger the failover
and the reversal of the link.
Certain line module and IOA combinations support physical level redundancy. The
redundancy feature enables a primary Gigabit Ethernet link to fail over to the secondary
link without signaling higher-layer protocols and by maintaining the same MAC address
on the link. The preservation of the same MAC address on the link also retains bindings
to the MAC address (for example, ARP entries). When the OAM entity signals that a
health monitoring threshold is exceeded, the event can trigger the failover to the secondary
link.
JunosE Software implements the Marker Responder segment of the Marker protocol. If
the OAM entity signals a link event, such as the exceeding of a high threshold value, using
the health monitoring system, then Marker Response PDUs are not sent in such
circumstances.
OAM Feature Overview on page 230
OAM Elements Overview on page 227
Configuring 802.3ah OAM Link-Fault Management on page 238
Guidelines for Configuring 802.3ah OAM Link-Fault Management on page 237
Keep the following points in mind when you configure OAM link-fault management on
Ethernet interfaces:
The OAM application transmits and receives an OAM PDU at a maximum frequency
of every 100 milliseconds (10 OAM PDUs/sec) on every port on the set of IOAs for a
line module. The most impact on performance might occur on ES2 4G LMs with two
GE-8 I/O modules (16 ports) that cause 160 OAM PDUs to be transmitted per second.
Also, the OAM application must query MAC-layer statistics (up to 6-8 for frame errors)
every 10 seconds and errored symbol statistics per second.
Because the outage time of the forwarding controller can last up to about 15 seconds
or longer, the 802.3ah OAM feature does not support unified ISSU. The link-fault
management of Ethernet interfaces is halted during a unified ISSU operation. Monitoring
resumes immediately after the unified ISSU operation is completed.
Although OAM configurations on an interface are preserved during a stateful SRP
switchover procedure, the retention of such OAM settings depends on the time that
the stateful SRP switchover process takes to complete. If the stateful SRP switchover
operation causes a traffic disruption of more than two seconds, the previously
configured OAM settings are affected. We recommend that you configure the number
of PDUs that are failed to be received by an OAM entity before it generates a link
fault/down event to be greater than two, and the high and low thresholds for an error
to be exceeded on an Ethernet OAM interface to be more than two seconds.
802.3ah OAM functionality is not supported on SRP Ethernet interfaces. Also, JunosE
Software does not support unidirectional operation of Ethernet OAM links, which enable
Chapter 7: Configuring IEEE 802.3ah OAM Link-Fault Management
237
Advertisement
Chapters
Table of Contents
Troubleshooting
