CATALYST TROUBLESHOOTING

1. Power On Self Test (POST) ” Diagnostics performed on the internal system architecture on power up.

2. Module LEDs ” Indicators of the module component status or speed.

3. Catalyst switching methods :

   • Fast-forward ” Begin forwarding the frames or packets immediately after receiving the destination port address information.

   • Store-and-forward ” Receives the entire frame or packet before making a forwarding decision.

   • Fragment-free ” Verifies that the frame or packet not fragmented before sending.

4. Commands used only on Set/Clear based IOS switches:

   • set span ” This command is used to copy packets from one port to another.

   • show arp ” Displays switch ARP entries.

   • show cam dynamics ” Displays CAM entries.

   • show config ” Displays the running configuration.

   • show interface ” Displays the SCO and SLO interface information.

   • show log ” Displays the switches error log.

   • show modules ” Displays information on all the installed modules on the switch.

   • show port ” Displays the port, module, or system information.

   • show spantree ” Displays spanning tree information for a VLAN or port.

   • show system ” Displays the switch's system information.

   • show test ” Displays diagnostic test results.

   • show trunk ” Displays individual port, module, or the entire system switch trunk information.

   • show version ” Displays the software and hardware versions.

   • show vlans ” Displays the VLAN information configured on the switch.

   • show vtp domain ” Displays the VTP domain information configured on the switch.

   • clear arp ” Clears the entire ARP cache.

   • clear cam ” Deletes CAM able entries.

   • clear counters ” Clears all MAC and port counters on the switch.

   • clear trunk ” Resets all trunk port information from the trunk table.

   • clear vlan ” Deletes a VLAN from the VTP management domain.

   • debug spanning events ” Displays real-time STP topology change information.

   • debug vlan packets ” Displays real-time VLAN error information.

5. Commands used on a Cisco Catalyst CLI based IOS switch:

   • show arp ” Displays switch ARP entries.

   • show running-config ” Displays the running configuration.

   • show interface ” Displays the SCO and SLO interface information.

   • show module ” Displays information on all the installed modules on the switch.

   • show spantree ” Displays spanning tree information for a VLAN or port.

   • show system ” Displays the global Ethernet configuration.

   • show diagnostics ” Displays diagnostic test results.

   • show version ” Displays the software and hardware versions.

   • show vlan ” Displays the VLAN information configured on the switch. The summary syntax displays a summary of the VLAN information.

   • clear arp ” Displays the entire ARP cache.

   • clear cam ” Deletes CAM able entries.

   • clear counters ” Clears all MAC and port counters on the switch.

6. To configure an IP address on a CLI based IOS switch, remember these facts:

   • Use the interface vlan command followed by the VLAN number.

   • Set the IP address with the ip address command followed by the IP address of the switch for the particular VLAN and the subnet mask.

   • The native VLAN address becomes active after the configuration change. The IP address of other VLANs becomes active and pingable after the first device in the VLAN attaches to a port on the switch assigned to that VLAN.