Troubleshooting Flowchart; Solution - H3C S5560-EI Series Troubleshooting Manual

Troubleshooting flowchart

Figure 21 Troubleshooting Layer 3 forwarding failure

Solution

To resolve the problem:
1. Verify that the port is not faulty (due to hardware or configuration problems).
If the port is faulty, follow the solution in
2. Verify that the ARP entries are correct:
a. Execute the display arp command to verify that the ARP entries are correct.
If the switch has not learned the APR entries or incorrect ARP entries exist, execute the
debugging arp packet command to locate the problem.,For the APR entries that are still not
learned, execute the arp static command to configure static ARP entries.
b. Execute the display mac-address command to verify that the output interfaces in the MAC
address entries and ARP entries are the same.
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.
"Layer 2 forwarding failure" to troubleshoot the problem.
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