I am handling the network with a lot of layer3, layer2 switches. There is a need to clean up the vlans that is no longer in use. Some vlans have vlan interface ip and some vlans do not have interface IP. The VTP operating mode is transparent.
Is there a way to identify the the vlan that is no longer in use and remove it without affect the existing production environment,.
The best way I can think of is to investigate where the VLANs are currently spanning to and if they are actually being used in those locations.
If you were to enter the command "show spanning-tree vlan x" at the core layer - you can see where the VLAN is currently spanning to (assuming you have SOME VLAN pruning in place, this will be easier). Once you determine where the VLAN is spanning, you can log into those switches and determine if that VLAN is actually being used or assigned to any ports "show vlan brief".
The faster/riskier way to decide whether they are in use or not would be to take a look at the MAC address or ARP tables of that VLAN and determine if there are any entries. If there are no entries, there is a decent chance that VLAN is not being used any longer. If there are entries, then the VLAN is probably in use and needed by the environment. You can log into the core layer and type "show mac address-table vlan x" or "show ip arp vlan x" to view the entries.
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