Accidentally Set Server Switch as VTP Client Mode
Mistake happens, whether we like it or not. A network administrator can mistakenly reconfigure operating mode of the server switch to VTP client. Only Server switches can create, delete, and modify VLANs, by reconfiguring the sever switch to VTP client mode, you lose all ability to create, delete, and manage VLANs within your network environment, all initial network administrative configuration will be lost. VTP client switches do not store VLAN information in NVRAM, they need to refresh the VLAN information after a reload.
Solution
Configure a second switch in the same domain as a VTP server. It is not uncommon for small networks that use VTP to have all the switches in VTP server mode. If the network is being managed by a couple of network administrators, it is unlikely that conflicting VLAN configurations will arise.
