Cisco vtp client 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.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.A typical setup involves at least one switch configured as a VTP Server, and multiple switches configured as VTP Clients.All VLAN information such as VLAN number and VLAN name is stored locally, on a separate NVRAM from where the 'startup-config' is stored.This happens only when the switch is in VTP Server mode.However, for those who noticed, there is a new concept introduced in the above diagram that we haven't spoken about: The VTP Domain.The VTP Domain, also known as the VLAN Management Domain, is a VTP parameter configured on every switch connected to the network and used to define the switches that will participate in any changes or updates made in the specified VTP domain.

At this point we are only referencing the VTP Domain concept as this is also analysed in greater depth further on, so let's continue with the VTP modes!For small networks with a limited number of switches and VLANs, storing all VLAN information on every switch is usually not a problem, but as the network expands and VLANs increase in number, it becomes a problem and a decision must be made to select a few powerful switches as the VTP Servers while configuring all other switches to VTP Client mode.The diagram above shows a Cisco Catalyst 3550 selected to take the role of the network's VTP Server since it is the most powerful switch.VTP, a Cisco proprietary protocol, was designed by Cisco with the network engineer and administrator in mind, reducing the administration overhead and the possibility of error as described above in any switched network environment.When a new VLAN is created and configured on a switch without the VTP protocol enabled, this must be manually replicated to all switches on the network so they are all aware of the newly created VLAN.

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