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New Member

Separate VTP domains. Will they still pass traffic ?

Hello,

We have a need to connect a large customer of ours to our core network.*

Obviously we do not want to use the same VTP domain as this customer or share VTP information. I realise that not using the same VTP domain as our customers will prevent sharing of VTP information, but will traffic still be passed between VLANs with the same name/id ? e.g We want traffic on VLAN 23 on our network to be passed over our trunk link to the customer. Documentation I have found doesn't explain the above clearly:

i.e. VTP will not share VTP information between different domains. But will traffic still be passed between different domains over trunk links ?

* We are using transparent LAN over cable, so we need the customer cable modem VLANs to be visible to the customer's core network.

4 REPLIES

Re: Separate VTP domains. Will they still pass traffic ?

Yes, hopefully you will be able to transmit traffic between two different VTP domain. It's only VTP operation that will be segmented at the boundary.

The only minor problem that you could experience is that I don't think there will be trunking negotiation between different VTP domains (i.e. DTP will not automatically form a trunk at the boundary). You will thus need to statically configure your trunks.

Regards,

Francois

New Member

Re: Separate VTP domains. Will they still pass traffic ?

Hi Francois,

Thank you very much for the reply. I just have an additional question in regards to static trunking setup. We are using a 3550, will the below be enough for static trunking configuration from our side of the link ?:

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 23,25,27,29,33,35,37,39

switchport mode trunk

Re: Separate VTP domains. Will they still pass traffic ?

HI

I think for this u need to have the above vlans in the other vtp domain or switch.

Thanks

Mahmood

Re: Separate VTP domains. Will they still pass traffic ?

Hi Friend,

Yes the config is perfect but I will also recommend you to configure the interface to stop sending DTP packets.

Use the "switchport nonegotiate" interface configuration command to specify that Dynamic Trunking Protocol (DTP) negotiation packets are not sent on the Layer 2 interface. The switch does not engage in DTP negotiation on this interface

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 23,25,27,29,33,35,37,39

switchport mode trunk

switchport nonegotiate

HTH, if yes please rate the post.

Ankur

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