Nowadays we have to configure VTP domains with Layer 3 switches as VTP servers. Normally at the core or at distribution
we have switches in redundancy. When we have an probelm to solve, we work on one switch and when we put it back in production....Bam! We have lost all the VLAN information.
The reason behind this is that when VTP servers are configured, they keep on exchanging info. Each time information is changed, the VTP version is increased by one. The VTP information with the highest number is treated as the most recent. So once you put this back, it replicates all the information on the other servers and you get information on all the servers across the network which you actually don't need.
To overcome this, before playing on any Layer 3 switch configured as a VTP server, change the VTP domain to some other name. Then, before putting it back online, change it to the old domain name.
The command is:
set vtp domain