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a.
If the statistics are not zero, the following issues might have occurred:
−
Inconsistent configuration
—Verify that the local and peer ports have the same
configuration (including speed and duplex mode). If they are not the same, modify the
configuration of the local port.
−
Interface hardware failure
—To test such a failure, connect the cable that is connected
to the local port to a correctly operating port (for example, Port A) with the same
configurations as the local port. If Port A forwards traffic correctly, you can determine
that the hardware of the local port fails. In this event, you must replace the local port with
a correctly operating port.
−
Transceiver module, fiber, or twisted pair failure
—To test and resolve such a failure,
replace the transceiver module, fiber, or twisted pair with a good one.
b.
If the issue persists, contact H3C Support.
When you contact H3C Support, provide the following diagnostic information if packet loss
occurs on the chip port with which the interface is associated:
2.
Verify that packets are not mistakenly filtered out by ACLs:
a.
Examine the ACL and QoS policy configurations for packet filtering on the port, on the VLAN
of the port, or globally. If packets are mistakenly filtered out, modify the ACL or QoS policy
configuration.
−
To display the ACL configuration on the port for packet filtering, execute the
display
packet-filter
command.
−
To display the QoS policy configuration on the port, execute the
display qos policy
command.
−
To display the QoS policy configuration on the VLAN of the port, execute the
display
qos vlan-policy
command.
−
To display the global QoS policy configuration, execute the
display qos policy
global
command.
b.
Verify that packets are not filtered out by ACLs automatically created by some features.
−
Execute
the
display this
command in Ethernet interface view to verify that the
ip
source binding
or
ip verify source
command is configured on the port. To
display source guard binding entries, execute the
display ip source binding
or
display ipv6 source binding
command. If IP source guard is configured but the
packets match no entry, further troubleshoot the issue based on the way the binding
entries are created.
−
Determine whether the port is configured with the portal authentication. If portal
authentication is configured, packets of users that fail to pass the portal authentication
will be dropped by the port. Use the
display portal interface
command to display
the portal configuration information of the specified VLAN interface. Determine whether
the portal authentication can be disabled based on the network conditions. To disable
the portal authentication, use the
undo portal server server-name
command in
VLAN interface view of the VLAN to which the port belongs.
−
Use
the
display dot1x
command to check whether 802.1X EAD assistant is enabled
on the interface.
If 802.1X EAD assistant is enabled on the interface, packets will be discarded for
unauthenticated users who access the network segments other than the Free IP.
−
Determine whether MFF is configured on the VLAN to which the port belongs. Use the
display mac-forced-forwarding vlan
command to display the MFF information
of the specified VLAN. If no gateway information is displayed in the output, verify that
ARP snooping is correctly configured based on the MFF operation mode.