Showing results for 
Search instead for 
Did you mean: 

Best Design For Datacenter using Transparent Mode.

ajay chauhan
Level 7
Level 7


I have backup enviroment which has got 50 Edge switches and one core switch. I need extended vlan so need to convert in transparent mode .so is it required to created all vlans created on core to replicate manually on all edge swicthes ? If i dont do that way and create vlan on egde swicthes as per requirment but not on all swicthes is that a bad design ?

Need practical approch how it is done in real world data centers.



6 Replies 6

Level 7
Level 7

Ajay! What's up I enjoy all your posts. So from what I take out of this, you have a backup enviornment which has gone 50 edge switches and one core switch? Also, you need extended vlans so you need to convert the switches to transparent mode? Is this correct? I see you have all your vlans created on core and you want them to be created on all edge switches?

You have understood the requirement correctly .

Well, I was gunna suggest having your CS as the VTP server, access switches as clients, and then use VTP to propagate the vlans down to the access switches. Then you can convery the clients to transparent mode, which will still keep all the vlans since there in the vlan.dat file, but since you need "extended vlans" I guess that won't be the case. Since, your wanting to do Transparent, I would just create them all on the core switch, and then you can create the appropriate commands in notepad, and just do a copy and paste on the access switches to speed up time. Obviously you will want to configure the trunks appropriately for the vlans.

I agree with it but looking for some best practice. Might be all the edge swicthes are not going to use same vlans.

what does cisco says  all vlans on all edge swicthes ?



Hi John,

Correct me if I'm techincally wrong, if the Vlan Created on the Core Switch has to be propogated to the edge switches, why should the edge swtiches be on the Transparent Mode. Transparent mode does not update its vlan.dat file.

why can't we have CS as the VTP Server and the Edge Switches as the VTP clients so that all the Vlan informations are propogated from the CS to Edge switches and we can have all of them in sync.

Any specific reason why the edge switches have to be in the transparent mode?


Well, the reason for transparent vlans are

- To manually configure your vlan database
- To stop incorrect information about vlans from propagating to your vlan database
- To use extended range VLANs

With normal VLANs you can only use VLAN id 1 to 1005.

When the switch is in VTP transparent mode and the enhanced software image is installed,
you can also create extended-range VLANs from 1006 to 4094

Review Cisco Networking for a $25 gift card