Lower layer network connects NE80E with FE through the switch. NE80E fails to ping the address of opposite direct switch.
1. Test the cable and the port, it is normal.
2. Check port protocol and it is forced full-duplex. Change it as self-negotiation and it can be negotiated as 100M full-duplex. It is still problematic.
3. Use display cpu slot command and CPU usage of the board reaches 97%. Disconnect the cable between NE80E and direct switch. CPU recovers.
4. Check lower network and there is loop. Resolve loop problem and direct cable between NE80E and switch. It can ping opposite address.
1. The cable or port id problematic.
2. The link protocol does not match.
3. CPU usage of NE80E is high and cannot handle ICMP packet in time.