An extended-range VLAN is numbered from 1006 through 4094 on Cisco switches. Earlier IOS versions reserved this range for internal applications; later versions made it available for user-created VLANs. section 13.2.3
VTP support determines how these VLANs are created and propagated:
- VTP versions 1 and 2 support only normal-range VLANs, numbered 1 through 1005. section 13.3
- VTP version 3 allows the primary server to create and propagate extended-range VLANs; only one switch can be primary. section 13.2.3
- Before VTP version 3, creating an extended-range VLAN required transparent mode, which prevented participation in the VTP domain. 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.
A CLI sequence shows VTP version 3 rejecting VLAN creation until the switch becomes the primary server. section 13.2.3
