VTP domain split into two...

[jclj]

Hello, I have a network where all of the vlan ip address are on the core (6509) switch and VTP replicates the vlans to other switches connected to the core. What I would like to do is move some vlans onto a lab (4506) switch and break VTP into two domains. Currently, the lab switch is connected as a trunk and has a static route of 0.0.0.0 0.0.0.0 to the core. The interface is configured as a switchport.

My questions:

1. since the port on the lab to core switch is configured as a switchport it's not routing, correct? So I can change it to "no switchport" and add an ip address to the interface and then configure ospf for dynamic routing.

2. Will this, effectively, create/separate my VTP domain?

3. Do you see any issues with this?

Thanks

[ahmedshoaib]

Hi;

Please find the answer below as per your queries:

1- Switchport indicate that your port configured as L2. With "no switchport" command port become L3 then assign IP address and run routing protocol (static or dynamic) to exchange routes.

2-Via task-1 you not only segregate VTP domain you can also divide your network in multiple routing domain and need to run routing protocol to exchange routes.

3- I don't see any issue. It's total depend on network requirement.

Thanks & Best regards;

[Joseph W. Doherty]

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Posting

#1 You can route across switch ports that are access or trunk using SVIs.  However, as VTP replication needs a trunk, changing the port to a routed port will block the VTP replication.

#2 Yes, although it can also be blocked by the devices on the two sides of a trunk being in different VTP domains (which I would recommend regardless whether you reconfigure the port or not).

#3 Yes, if you don't change your lab's VTP domain, and you're using VTP versions 1 or 2, you're setting yourself up for the classical accidental "zap" of your prod VTP domain.  (Even if you do use a different VTP domain for the lab, be very careful in how you add VTP devices to your VTP domains, especially a prod VTP domain.  Recommend you read up on the proper/recommended procedure.)

[jclj]

"#3 Yes, if you don't change your lab's VTP domain, and you're using VTP versions 1 or 2, you're setting yourself up for the classical accidental "zap" of your prod VTP domain.  (Even if you do use a different VTP domain for the lab, be very careful in how you add VTP devices to your VTP domains, especially a prod VTP domain.  Recommend you read up on the proper/recommended procedure.)"

This is exactly what I'm worried about. As long as I make it a layer 3 port VTP won't cross the link and I should be ok, right? I can change the VTP domain on the lab switches later?

[ahmedshoaib]

Hi;

VTP is L2 Technology, it will not cross the L3 domain. If you configure the port b/w Production & Lab as L3 then you need to do routing b/w both network.

Thanks & Best regards;

[Joseph W. Doherty]

Correct.