Related Commands - H3C S5560-EI Series Troubleshooting Manual

If the port belongs to an aggregation group, execute the display link-aggregation verbose
command to identify the port status. When the port is an Unselected port, it cannot forward
traffic. Locate the reasons why the port is in Unselected state. For example, the attribute
configurations of the port are different from the configurations of the reference port.
Identify whether the port is blocked by smart link. Use the display smart-link group command
to view the port status. If the state of the port is STANDBY or DOWN, the port cannot forward
traffic.
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4. Examine the following configurations that might cause packet loss:
VLAN configuration—Execute the display this command in Ethernet interface view to verify that
the port is in the VLAN of the packets. If it is not, add the port to the VLAN.
Blackhole MAC address entries—Execute the display mac-address blackhole command to
display blackhole MAC address entries. If the packets are discarded because they match a
blackhole MAC address entry, delete the entry. To delete the blackhole MAC address entry,
execute the undo mac-address blackhole mac-address vlan vlan-id command.
Rate limit—Execute the display qos lr interface command to display the rate limit configuration
on the port. If rate limit is configured on the port, make sure the committed information rate (CIR)
and the committed burst size (CBS) are appropriate. To adjust the CIR and CBS values, execute
the qos lr { inbound | outbound } cir committed-information-rate [ cbs committed-burst-size ]
command.
Storm suppression—Execute the display this command in Ethernet interface view to display the
configuration of storm suppression. Storm suppression includes broadcast suppression,
multicast suppression, and unknown unicast suppression. To adjust the suppression thresholds,
execute the broadcast-suppression, multicast-suppression, and unicast-suppression
commands, respectively.
5. Verify that no congestion occurs by using the display qos queue-statistics interface command.
If congestion occurs, locate and resolve the problem by referencing related congestion
management documents.
6. If the problem persists, contact H3C Support.

Related commands

This section lists the commands that you might use for troubleshooting Layer 2 packet loss failure.
Command
display interface
display dot1x
display packet-filter
display qos policy
If the state of the port is DOWN, locate the reason for the port to be down. The possible
reasons include: its uplink device is configured with monitor link, the link of the port fails, or
the port is shut down. Further troubleshoot the problem based on the reason for the port to
be down.
If the state of the port is STANDBY, perform an active/standby switchover in the smart link
group.
Description
Displays Ethernet interface information.
Displays information about 802.1X.
Displays whether an ACL has been successfully
applied to an interface for packet filtering.
Displays user-defined QoS policy configuration
information.
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