Cisco Switching Troubleshooting Command Details
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show ip interface brief
show mac address-table
show mac address-table | include
show mac address-table vlan
show spanning-tree
show spanning-tree vlan
show cdp neighbors
show cdp neighbors detail
show interface
show running config interface
show running-config | include
show running-config | begin
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Show mac address-table
This command shows all MAC addresses the switch is aware of and each address’
associated VLAN and physical port. By default this command shows the full contents of
every VLAN that traverses the switch so I recommend you filter the output with one of
the following variations:
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show mac address-table dynamic – Display only learned MAC addresses.
show mac address-table vlan <vlan id> – Show results for only the specified
VLAN.
show mac address-table | include xxxx – Find out which port a known device
Just replace xxxx with the last four digits of a device’s MAC
address. Note that the MAC address must be lower case or it will not match.
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"show log"
Last reboot information, use “show log.” You’ll find a wealth of information about the switch’s
hardware, software, interfaces, and more.
