Understanding Port Errors

Typically, at the port level, you are interested in Layer 1 and Layer 2 errors. Some of the common errors are bad cable, alignment issues, frame check sequence (FCS), and collisions seen on the port. Example 12-9 shows the output from the show port command.

Example 12-9 shows excessive collisions seen on port 10/3. Recall from Chapter 1, “LAN Switching Foundation Technologies,” excessive collisions are associated with too much traffic on the segment or too many hosts contenting to access the segment.

Example 12-9. Examining Port Fields
Switch1 (enable) show port 10/3 * = Configured MAC Address Port Send FlowControl Receive FlowControl RxPause TxPause admin oper admin oper ----- -------- -------- --------- --------- ...

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