Troubleshooting Flowchart; Solution - H3C S5120V3-EI Series Troubleshooting Manual

Troubleshooting flowchart

Figure 8 Troubleshooting Layer 3 forwarding failure
Layer 3 packet loss
The port is faulty?
ARP entries are correct?
Yes
Route entries are correct?
Yes
Contact H3C Support

Solution

To resolve the issue:
1. Verify that the port is not faulty (due to hardware or configuration issues).
If the port is faulty, follow the solution in
2. Verify that ARP entries are correct:
a. Execute the display arp command to verify that ARP entries are correct.
−
−
b. Execute the display mac-address command to verify that the output interfaces in the MAC
address entries and ARP entries are the same by using the display mac-address
command.
If the output interfaces are not the same, execute the reset command to clear the ARP
entries. Then the switch can learn ARP entries again.
3. Verify that route entries are correct:
a. Execute the display ip routing-table command to verify that route entries are correct.
If incorrect route entries exist, troubleshoot the protocol that learns the route entries.
b. Execute the display fib command to verify that the output interfaces in the FIB entries and
route entries are the same.
If the output interfaces are not the same, execute the reset command to clear the route
entries. Then the switch can learn route entries again.
4. If the issue persists, contact H3C Support.
Yes
No
No
No
If incorrect ARP entries exist, execute the debugging arp packet command to locate
the issue.
If the switch learns no ARP entries, you can execute the arp static command to
configure static ARP entries.
Troubleshoot the port
Troubleshoot ARP
entries
Troubleshoot route
entries
"Layer 2 forwarding
29
Yes
Resolved?
No
Yes
Resolved?
No
Yes
Resolved?
No
End
failure" to troubleshoot the issue.