10
−
If the port is enabled with IPv4SG and has IPv4SG bindings or IPv6SG bindings
configured, determine if the packets are discarded for lack of matching IPSG bindings.
Edit the IP source guard settings as needed. To display the IPv4SG and IPv6SG
bindings, execute the
display ip source binding
and
display ipv6 source
binding
commands.
3.
Verify that the port is not blocked:
{
Execute the
display stp brief
command to determine if the port is set to the
Discarding
state by STP (a port in
Discarding
state cannot forward traffic). If the port is in
Discarding
state, disable STP on the port or configure the port as an edge port if the port is
connected to a terminal device.
{
If the port belongs to an aggregation group, execute the
display link-aggregation
verbose
command determine if the port is in
Unselected
state (a port in
Unselected
state
cannot forward traffic). Find the cause if the port is in
Unselected
state. For example, the
attribute configurations of the port are different from the configurations of the reference port.
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 by using 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) is appropriate. To adjust the CIR value, execute the
qos lr
{
inbound
|
outbound
}
cir
committed-information-rate
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.
Execute the
display interface
command to check the bandwidth usage on the port for
risks of congestions.
If congestion occurs, locate and resolve the problem by referencing related congestion
management documents.
6.
If the issue persists, contact H3C Support.
Related commands
This section lists the commands that you might use for troubleshooting Layer 2 forwarding failure.
Command
Description
display interface
Displays Ethernet interface information.
display ip source binding
Displays IPv4 source guard binding entries.
display ipv6 source binding
Displays IPv6 source guard binding entries.
display link-aggregation verbose
Displays detailed information about the aggregation groups
that correspond to the aggregate interfaces.
display mac-address blackhole
Displays blackhole MAC address entries.
display packet-filter
Displays whether an ACL has been successfully applied to
an interface for packet filtering.
