Connectivity Problems

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.

Example

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

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