Use the following general tasks to isolate connectivity problems:
Check physical connectivity. Verify if an alarm for link or port down exists.
Check the link state by viewing the show interface {gigabitEthernet|loopback|vlan} command output.
Use tools like ping or trace to verify if the connectivity issue is localized to an individual port or VLAN.
Try to localize the affected range of ports and slot.
If you contact technical support staff to help troubleshoot connectivity problems, always provide source and destination IP pairs to facilitate in troubleshooting. Be sure to provide both working and non-working pairs for comparison.
Switch:1#show interface vlan =============================================================================================== Vlan Basic =============================================================================================== VLAN MSTP ID NAME TYPE INST_ID PROTOCOLID SUBNETADDR SUBNETMASK VRFID ------------------------------------------------------------------------------------------------ 1 Default byPort 0 none N/A N/A 0 2 VLAN-2 byPort 0 none N/A N/A 0 50 mcast_smlt_3 byPort 1 none N/A N/A 0 60 mcast_smlt_4 byPort 1 none N/A N/A 0 All 4 out of 4 Total Num of Vlans displayed ============================================================================== Vlan Port ============================================================================== VLAN PORT ACTIVE STATIC NOT_ALLOW ID MEMBER MEMBER MEMBER MEMBER ------------------------------------------------------------------------------ 1 1/5-1/8,1/10-1/48, 1/5-1/8,1/10-1/48, 2/2-2/4 2/2-2/4 2 50 1/1,2/1/3-2/1/4 1/1,2/1/3-2/1/4 60 1/3-1/4 1/3-1/4 All 4 out of 4 Total Num of Port Entries displayed ============================================================================== VLAN VRF Association ============================================================================== VLAN VRF ID NAME ------------------------------------------------------------------------------ 1 GlobalRouter 2 GlobalRouter 50 GlobalRouter 60 GlobalRouter 4086 GlobalRouter 4087 GlobalRouter --More-- (q = quit)