Vtp status not updating
The logic behind this setup is that all information regarding VLANs is stored only on the VTP Server switch from which all clients are updated.
Any change in the VLAN database will trigger an update from the VTP Server towards all VTP clients so they can update their database.
Lastly, be informed that these VTP updates will only traverse Trunk links.
This means that you must ensure that all switches connect to the network backbone via Trunk links, otherwise no VTP updates will get to your switches.
All VLAN information such as VLAN number and VLAN name is stored locally, on a separate NVRAM from where the 'startup-config' is stored.
The method and frequency by which these updates occur is covered in much detail on the pages that follow, so we won't get into any more detail at this point.Despite the variety of versions, it also operates in 3 different modes: Server, client and transparent mode, giving us maximum flexibility on how changes in the network effect the rest of our switches.To help keep things simple and in order to avoid confusion, we will work with the first version of the VTP protocol - VTP v1, covering more than 90% of networks.In most networks, the clients connect directly to the VTP Server as shown in our previous diagram.If, for any reason, two clients are cascaded together, then the information will propagate downwards via the available Trunk links, ensuring it reaches all switches: The diagram shows a 3550 Catalyst switch configured as a VTP Server and 4 Catalyst 2950 switches configured as VTP Clients and cascaded below our 3550.
Below you'll find the 3 modes the VTP protocol can operate on any switch throughout the network: Each mode has been designed to cover specific network setups and needs, as we are about to see, but for now, we need to understand the purpose of each mode and the following network diagram will help us do exactly that.