Setup Guide

You can enable the capability to detect uneven trac distribution in the member links of a HiGig link bundle on a line-card or SFM NPU. You
can also enable a notication to be sent using alarms and SNMP traps. The algorithm used to determine uneven distribution of trac is
predened.
Monitoring HiGig link bundles allows you to view and analyze unequal trac ow in backplane port channels and take corrective action.
Alarms are generated if the link-bundle trac threshold is greater than the congured threshold and the unevenness is greater than 10
percent between links for three successive rate-intervals. Alarms are removed when the link-bundle threshold is lower than the congured
threshold and the unevenness is less than 10 percent between links for three successive rate intervals.
An alarm includes the following information:
• Line-card or SFM NPU unit and HiGig port-channel ID in the format: hg-port-channel slot slot/npu-id/hg-port—
channel-id
• Alarm: triggered or cleared
Examples of the system log messages triggered when the threshold for a HiGig link bundle/port channel is exceeded are:
• %STKUNIT0-M:CP %SWMGR-5-HG-BUNDLE_UNEVEN_DISTRIBUTION: Found uneven distribution in hg-port-channel 0/5/0
• %STKUNIT0-M:CP %SWMGR-5-HG-BUNDLE_UNEVEN_DISTRIBUTION_ALARM_CLEAR: Uneven distribution in hg-port-
channel 0/5/0 got cleared
Guidelines for Monitoring HiGig Link-Bundles
When conguring HiGig link-bundle monitoring on the backplane, follow these guidelines:
• By default, the capability to monitor the trac distribution in a HiGig link bundle on a line-card or SFM NPU is disabled.
• Each line-card NPU uses two HiGig link bundle for its backplane links to connect each SFM (spine) NPU. The convention used to
identify a HiGig link-bundle interface is: hg-port-channel slot/npu-id/0, where slot species the line-card slot number (0–11), npu-id
species the NPU ID number (0), and HiGig port-channel ID which is in the range (0-2) for a line-card NPU
• Each SFM NPU uses a separate HiGig link bundle to connect to each line-card (leaf) NPU. The convention used to identify a HiGig link-
bundle interface is: hg-port-channel slot /higig-port-channel-id, where slot species SFM slot number which is in the range of 0 to 1,
npu-id species the NPU ID number (0)
• HiGig link-bundle monitoring starts only when:
– You enable monitoring for a specied HiGig link bundle using the hg-link-bundle monitor command.
– Bundle usage for egress trac exceeds the threshold congured with the hg-link-bundle monitor trigger-threshold
command.
Alarms are generated only when link-bundle trac levels are high. At low trac levels, only one or two signicant ows may cause
unevenness. However, uneven trac distribution across links during low-trac periods is not critical and does not trigger an alarm.
• You can enable SNMP traps and syslog messages to be generated when an uneven trac distribution is detected in a HiGig link bundle.
• Trac distribution in a HiGig link bundle is calculated as the bandwidth-weighted mean use of all links in the bundle. This calculation is
performed only on links that are up in their operational status.
• The rate interval used to poll trac distribution in member links in a HiGig link bundle is user-congurable. The default polling interval is
15 seconds.
• The trigger threshold species the percentage of total bundle bandwidth used to issue an alarm for uneven trac distribution. The
default is 60 percent. When the mean link utilization is below this value, uneven link-bundle trac is not reported.
The dierence in utilization percentage between the high-used link and low-used link determines the alarm condition. Alarm reporting
for link-bundle monitoring is based on the same algorithm used for LAG/ECMP. An alarm condition occurs when the unevenness in link-
bundle utilization exceeds 10 percent of the congured threshold and remains active until trac on member links falls below the trigger
Interfaces
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