VLAN Trunking Protocol (VTP) in Nexus NX-OS – Slight Difference with IOS

VLAN Trunking Protocol (VTP) is also available in Nexus NX-OS. The creation, modification and deletion of VLAN are easy with the use of VTP. Like in the Cisco Catalyst switches, the configuration is just the same. There is not much difference when configuring it but there are some few things to take note. These things make it unlikeable to deploy VTP in a data center environment.

Firstly, let’s discuss VTP version 3. Do you recall what is VTP version 3? Ok, this is the 3rd version of VTP. So what’s the difference with this new version compare to old versions? VTP version 1 and 2 only support a normal range of VLANs from 1 – 1005 but VTP version 3 expands the VLAN range up to 4094. Yes, it is supporting the entire VLAN range! It also supports enhanced authentication where you can configure the password as hidden or secret. VTP version 3 also supports MST and transfer information of private VLANs. Not only that, there is primary server and secondary server concept here where the primary server is responsible for updating and sending updates to VLANs while secondary server serves as a backup. Interesting right? However, in Cisco NX-OS there is no VTP version 3. Yeah, after giving you a lot of exciting features, you cannot use it in Nexus.

There is, however, another limitation. IOS VTP pruning is only good for normal VLAN range but in Nexus 5K (Nx5K), it does not support VTP pruning at all.

In NX-OS, the default mode is disabled. Like the routing protocols that need to be enabled manually, you also need to manually enable VTP using the “feature vtp” command. Moreover, NX-OS supports VTP mode off. Off mode behaves like transparent mode but it does not forward VTP packets on trunks.