Do I need to create all VLANS on all switches?

[Joris Syen]

Hello,

I have some minor experience with Cisco switches but this is the case:

We will create a ring of 8 Catalyst 2960 (layer 2) switches that are connected via optical fiber.

The switches would be connected to each other using trunking on the fiber port.

VTP is not recommended by our supplier.

Now I am wondering, do I need to create every VLAN on every switch in order to make it able to trunk that VLAN?

If I would like a device in VLAN 66 on switch1 and on switch8, do I need to create VLAN 66 then also on switch 2-7?

Thank you.

Best Regards,

Joris

[Colin Mans]

Hi Joris,

Yes, if you plan to not use VTP, you will need to create all VLANs on all switches.In your case, this would mean that VLAN66 needs to be on switches 1 through 8.

Hope this answers your questions.

[Joris Syen]

Hello,

So even if I configure the Trunk ports for "ALL VLAN", I need to add these VLANs on every switch?

[Colin Mans]

Yes Joris,

The "ALL VLAN" is telling to allow all  VLANs that are created on the switch to be allowed over the Trunk port.

You can verify the VLANs that are currently on the switch with the command "show vlan".

To verify which VLANs are going over the trunk link, you can use the "show interfaces trunk"-command.

[jimmysands73_2]

Just curious....say he had 100+ switches, could he not setup a VTP server, then all others as clients....setup the vlans on the server...then when all was said and done, change them all to VTP transparent?

[Colin Mans]

Yes Jimmy,

This should also work, you can set up VTP to configure the VLANs and set it to transparant afterwards.      

[Joris Syen]

Would it be a good idea to just create all 255 VLANs beforehand on all switches using VTP and then disable VTP?

Then afterwords, we can see what VLANs will be used and what not? So if we then need an extra VLAN in the future, we can just pick one of the 255?

[Colin Mans]

This is not advisable.

first off all, you will have a larger than needed vlan database.

Secondly, this will make you have to configure all VLANs seperately on all switches, or make use of VTP.

[Joris Syen]

1. Larger then needed VLAN database, is this a disadvantage?

2. I prefer configuring more during initial integration, then having to update 8 or 9 switches every time I add a VLAN. This will be a lot of more work compared with doing this initially, this can be done via script or VTP before startup so there is no risc. Doing this during production seems more risc to me.

3. I will not have to take a new backup of 8 switches every time I add a VLAN, because the VLANs are already added?

So the only real disadvantage I see is the VLAN database that is larger then needed, is that a performance drop?

[Joseph W. Doherty]

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Posting

You could also just ignore your supplier's recommendation against using VTP.

The notable concern using VTP is accidentally erasing all your defined VLANs within your VTP domain.  This can be pretty well avoided by defining a VTP domain and using a VTP password, along with only having one switch defined in the server role.