CIT-solves problems in physical layer and Data Link Routing

Physical Layer symptoms
There are no components that can work normally on the physical layer of the faulty interface.
. The network is in the running status, but it is interrupted at a time, which is worse than that in the baseline status.
There is no connectivity between interfaces on the data link layer.
. Frame Error, line Encoding Error and synchronization error
. LED indicator light off, flashing or abnormal
. The utilization rate is too high.
The number of API errors has increased.
. Console message (error reported) appears
. System Log File message (error reported) appears
. Manage System alarm second data link layer symptoms
Components on the data link layer of the faulty link do not work anymore.
The link works, but it is worse than the baseline status.
. No connectivity at the network layer
. Frame error or encapsulation error occurred
The. address parsing error exists.
Too many CRC errors occur
. Surge in broadcast traffic
. MAC address loops between ports
. Console message (error reported) appears
. System Log message (error) pop-up
The management system alarm displays the Issue 3 isolation command
1. Terminal
. Ping
. Arp-
. Netstat-rn
. Ipconfig-a [ifconfig]
. Tracert [traceroute or winipcfg]
2. cisco IOS
. Ping
. Trace
. Debug
. Show version
. Show ip int brief
. Show interface
. Show cdp neighbor detail
. Show controller

IV isolation Guide
. Check the running status and Data Error Rate
. Make sure that the interface configuration is correct.
. Check cable configuration
. Check the wrong cable or connection
. Check the wrong cable Five correct the error command
. Arp-d ip-address
. Interface
. No shutdown
. Encapsulation
. Clock rate
. Controller
. Duplex {full | half | auto} or half-duplex full-duplex
. Speed {10 | 100 | auto} 6 Error Correction Guide
1. Ensure that the correct configuration of any device that may modify the configuration is saved. This provides the final way to restore the initial state to a known state.
Make Initial hardware and software configuration changes
. Evaluate and archive changes and change results
. Confirm that the changes have solved the problem without introducing new problems.
. Continue to change until the original problem is resolved.
. If necessary, you can obtain help from external resources
. After the problem is solved, archive the solution article entry: csh responsible editor: csh