【problem analysis】
1. Analyze the networking topology. As shown in the following figure, there are four rings on the customer's network: ring-1, ring-2, ring-3, and ring-4.
The IP address of the faulty PC500 is 10.18.7.33, which is located in ring-4.
Analyze the switch configuration. It is found that the SEP ring is used to connect the switch to the PC500.
2. Run the display arp command on the core switch. It is found that the ARP entry of PC500 10.18.7.33 is learned from 2/0/3, but 2/0/3 belongs to ring-3.
At the same time, PC500 10.18.7.33 and PC500 10.18.7.28 repeatedly preempt g1/0/3. As a result, the two PC500s cannot be used.
【root cause】
PC500 physical connection is incorrect
【suggestion】
4. Check the physical connection of PC500 and correct the connection. In this example, PC500 of ring-4 is incorrectly connected to the host of ring-3.
5. For other PC500s, you can use the display arp command to locate the incorrect connection.
