The Switch from VTP Client to VTP Transparent

levitated · ‎03-26-2012

Hello,

First time posting here, pardon me if this is the incorrect forum or if this subject has been talked to death in other threads.

My current production network is setup using VTP in Client mode, and I am looking to enable VTP Transparent so I can enable the extended VLANs. My main question would be, would enabling VTP Transparent on my 6509 affect all of the access switches it is connected to? And if so, would changing all of the access switches to VTP Transparent allow them to regain connectivity quickly with little downtime? Or is there another way that I should be handling this situation to enable the extended VLANs?

Let me know if there are any command outputs that would help.

Thanks in advance!

Mike

vijay.swaminathan · ‎03-26-2012

Mike,

when you configure the VTP mode to "Transparent" the switch will not act upon the VTP updates.

ie., when you create a vlan on another switch and propogate this infomration to your switch configured as VTP Transparent, then your switch might not have this infomration updated on its vlan database.

Transparent mode just propogates the VTP infomration to another switch via trunk link and will not update its local database.

Also when you create a vlan locally it is not propogated to other switches as well.

-Vijay

Kyle McKay · ‎03-26-2012

There are certainly a few caveats when it comes to migrating from VTP client to transparent.

The biggest one that comes to mind is VTP Pruning. If you have the VTP pruning feature enabled on your network, I suggest you take extreme care during your migration. If a VTP client switch detects that there is nobody left on the VTP domain using a particular VLAN (because you've converted them to VTP transparent) it will prune that VLAN from the uplinks. We experienced this issue last year - it took awhile to figure out what exactly was happening.

Ideally you want to have a network that is in Client/Server mode or in Transparent mode - not both. (Transparent is preferable)

As long as your 6509 is running VTP Transparent mode 2 or greater, there should be no issues, as it will allow for the "relaying" of VTP messages between client/server and simply act as a forwarder.