Administrator Guide

● 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 specifies the line-card slot
number (0–11), npu-id specifies 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 specifies SFM slot number which is in
the range of 0 to 1, npu-id specifies the NPU ID number (0)
● HiGig link-bundle monitoring starts only when:
○ You enable monitoring for a specified HiGig link bundle using the hg-link-bundle monitor command.
○ Bundle usage for egress traffic exceeds the threshold configured with the hg-link-bundle monitor trigger-
threshold command.
Alarms are generated only when link-bundle traffic levels are high. At low traffic levels, only one or two significant flows may
cause unevenness. However, uneven traffic distribution across links during low-traffic periods is not critical and does not
trigger an alarm.
● You can enable SNMP traps and syslog messages to be generated when an uneven traffic distribution is detected in a HiGig
link bundle.
● Traffic 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 traffic distribution in member links in a HiGig link bundle is user-configurable. The default polling
interval is 15 seconds.
● The trigger threshold specifies the percentage of total bundle bandwidth used to issue an alarm for uneven traffic
distribution. The default is 60 percent. When the mean link utilization is below this value, uneven link-bundle traffic is not
reported.
The difference 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 configured threshold and remains active until traffic on
member links falls below the trigger threshold. If unevenness is recorded for three consecutive measurements, an alarm
event is generated. The rate interval defines the time interval between measurements.
Enabling HiGig Link-Bundle Monitoring
To enable the monitoring of HiGig link bundles, follow these steps.
1. Enable the monitoring of traffic distribution on the member links in a HiGig link bundle (port-channel).
CONFIGURATION mode
Dell(conf)#hg-link-bundle-monitor {sfm npu-id hg-port—channel hg-port—channel-id | slot
slot npuUnit npu-id hg-port—channel 0} enable
2. Specify the trigger threshold for HiGig link-bundle monitoring.
CONFIGURATION mode
Dell(conf)#hg-link-bundle-monitor trigger-threshold percentage
3. Specify the interval (in seconds) when HiGig link-bundle monitoring is performed.
CONFIGURATION mode
Dell(conf)#hg-link-bundle-monitor rate-interval seconds
4. Enable SNMP trap generation for HiGig link-bundle monitoring.
CONFIGURATION mode
Dell(conf)#snmp-server enable traps hg-lbm
5. Display the traffic utilization of member links in a HiGig link bundle (port channel).
EXEC, EXEC Privilege modes
Dell#show hg-link-bundle-distribution {sfm npu-id hg-port—channel hg-port—channel-id |
slot slot npuUnit npu-id hg-port—channel 0}
Interfaces
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