Troubleshooting Ethernet interfaces

This section provides troubleshooting information for common problems with Ethernet interfaces.

Failure to ping the directly connected device

Symptom

An Ethernet interface cannot ping the directly connected device.

Solution

To resolve the issue:

1.     Execute the display interface command and perform the following tasks:

¡     Verify that the interface is up.

¡     Verify that the speed and duplex mode of the local end match the speed and duplex mode of the peer end.

¡     Verify that the cable and interface are operating correctly by viewing the packet statistics of the interface.

¡     Verify that the transceiver module of the local end matches the transceiver module of the peer end if the interface is a fiber port.

2.     Use the display arp command to verify that the interface can receive ARP packets sent by the directly connected device. If not, use the debugging arp packet command to verify that the interface can send and receive ARP packets correctly.

3.     Use the debugging ip packet command to verify that the interface can send and receive packets correctly.

4.     Use the debugging ip icmp command to verify that the interface can send and receive ICMP packets correctly.

5.     If the issue persists, contact H3C Support.

Failure to forward packets

Symptom

An Ethernet interface on an intermediate router cannot forward packets.

Solution

To resolve the issue:

1.     Verify that the Ethernet interface can ping the directly connected device. If the ping operation fails, see "Failure to ping the directly connected device."

2.     Use the debugging ip packet command to verify that the interface can transmit packets correctly.

3.     If the issue persists, contact H3C Support.

¡     Execute the display hardware internal module interface-name interface-number status command in probe view to collect the status information.  

Packet dropping

Symptom

An Ethernet interface drops packets.

Solution

To resolve the issue:

1.     Determine whether the packets are dropped by the local end or the peer end by executing the following commands to compare the rates of the two ends:

¡     Execute the display counters rate inbound interface command on the local end to view the inbound traffic rate statistics.

¡     Execute the display counters rate outbound interface command on the peer end to view the outbound traffic rate statistics.

The end with a lower rate drops packets.

2.     Use the display interface command to view the traffic statistics for the interface to verify that no packets are dropped by the interface.

3.     If the issue persists, contact H3C Support.

¡      

Related commands

This section lists the commands that you might use for troubleshooting Ethernet interfaces.