vtp primary is a Cisco IOS privileged EXEC command that makes a VTP server the primary server for its VTP domain. In VTP version 3, only the primary server can create, modify, or delete VLANs; other servers act as secondary servers. section 13.2.3
Making SW1 primary
After enabling VTP version 3, SW1 cannot create VLAN 6 until it becomes primary. Enter `vtp primary` from privileged EXEC mode; from global configuration mode, use `do vtp primary`. The switch prompts for confirmation and then permits VLAN creation. Only one switch can be primary; making another switch primary changes the first to secondary. section 13.2.3
SW1(config)# vtp version 3 #1 SW1(config)# vlan 6 #2 VTP VLAN configuration not allowed when device is not the primary server for vlan database. #3 SW1(config)# do vtp primary #4 This system is becoming primary server for feature vlan #4 No conflicting VTP3 devices found. #4 Do you want to continue? [confirm] #4 SW1(config)# vlan 6 #5 SW1(config-vlan)# exit #5 #1 Enables VTP version 3 #2 Creates a VLAN #3 The command is rejected. #4 Makes SW1 the primary server #5 SW1 can now create VLANs.
Shows the rejected VLAN command, the `do vtp primary` invocation, confirmation prompt, and successful VLAN creation. section 13.2.3
