Junos® OS Ethernet Interfaces Configuration ... - Juniper Networks

Junos ®
OS 12.3 Ethernet Interfaces Configuration Guide
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• If graceful Routing Engine switchover (GRES) occurs, any collected ETH-DM statistics
are lost, and ETH-DM frame counts are reset to zeroes. GRES enables a router with
dual Routing Engines to switch from a master Routing Engine to a backup Routing
Engine without interruption to packet forwarding. For more information, see the Junos
OS High Availability Configuration Guide.
• Accuracy of frame delay data is compromised when the system is changing (such as
•
from reconfiguration). We recommend performing Ethernet frame delay measurements
on a stable system.
Ethernet Frame Delay Measurements Overview on page 238
• Starting an ETH-DM Session on page 264
• Guidelines for Managing ETH-DM Statistics and ETH-DM Frame Counts on page 256
• monitor ethernet delay-measurement operational command
• Junos® OS Ethernet Interfaces
Guidelines for Managing ETH-DM Statistics and ETH-DM Frame Counts
ETH-DM Statistics
256
• ETH-DM Statistics on page 256
• ETH-DM Statistics Retrieval on page 258
• ETH-DM Frame Counts on page 258
• ETH-DM Frame Count Retrieval on page 259
Ethernet frame delay statistics are the frame delay and frame delay variation values
determined by the exchange of frames containing ETH-DM protocol data units (PDUs).
• For a one-way ETH-DM session, statistics are collected in an ETH-DM database at the
router that contains the receiver MEP. For a detailed description of one-way Ethernet
frame delay measurement, including the exchange of one-way delay PDU frames, see
“Ethernet Frame Delay Measurements Overview” on page 238.
• For a two-way ETH-DM session, statistics are collected in an ETH-DM database at the
router that contains the initiator MEP. For a detailed description of two-way Ethernet
frame delay measurement, including the exchange of two-way delay PDU frames, see
“Ethernet Frame Delay Measurements Overview” on page 238.
A CFM database stores CFM-related statistics and—for Ethernet interfaces that support
ETH-DM—the 100 most recently collected ETH-DM statistics for that pair of MEPs. You
can view ETH-DM statistics by using the delay-statistics or mep-statistics form of the
show oam ethernet connectivity-fault-management command to display the CFM statistics
for the MEP that collects the ETH-DM statistics you want to view.
Table 24 on page 257 describes the ETH-DM statistics calculated in an ETH-DM session.
Copyright © 2012, Juniper Networks, Inc.