18
ipv6 source binding
command. If IP source guard is configured but the packets match no
entry, further troubleshoot the problem based on the way the binding entries are created.
−
Portal authentication
—When portal authentication is configured, the port discards the
packets of unauthenticated users. To display the portal configuration of the port or the
VLANs of the port, execute the
display portal interface
command. To cancel the portal
configuration on the port, execute the
undo portal
command in Layer 2 Ethernet interface
view. To cancel the portal configuration on the VLAN of the port, execute the
undo portal
server
server-name
command on the corresponding VLAN interface.
−
EAD fast deployment
—When EAD fast deployment is enabled, the port discards packets of
unauthenticated users except when the users only access a free IP. To display whether EAD
fast deployment is enabled on the port, execute the
display dot1x
command.
−
MFF
—To display the MFF configuration information of the VLAN to which the port belongs,
execute the
display mac-forced-forwarding vlan
command. If the output does not contain
the gateway information, examine whether the ARP snooping or DHCP snooping
configuration is correct.
3.
Verify that the port is not blocked:
{
Execute the
display stp brief
command to determine whether STP sets the state of the port to
discarding
. When the port is in
discarding
state, it cannot forward traffic. H3C recommends
disabling STP on the port, or configuring 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 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.
{
Execute the
display rrpp verbose
command to determine whether the port is down or RRPP sets
the state of the port to
blocked
. When the port is in down or blocked state, it cannot forward
traffic.
−
If the port is in down state, examine whether the port is physically or administratively shut
down.
−
If the port is in blocked state, find the reasons. For example, the roles of the primary and
secondary port on the master node are reversed, or the broadcast storm suppression
mechanism blocks the port because SRPT failure occurs in a multi-homed subring.
{
Execute the
display smart-link group
command to determine whether Smart Link sets the state
of the port to
standby
or
down
. When the port is in standby or down state, it cannot forward
traffic.
If the port is in standby state, set the port as the primary port.
If the port is in down state, the follow reasons might apply, and further troubleshooting is
required:
−
The uplink device is configured with Monitor link, and its uplink is down.
−
The link between the local port and its peer fails.
−
The local port is administratively shut down.
4.
Examine the following configurations that might cause packet loss:
{
VLAN configuration
—Execute the
display this
command in Ethernet interface view to display
whether the port is in the VLAN of the packets. If 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