One Network 2 buildings

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Nov 3rd, 2009
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I have a network that will be extended to another building. I have all the vlans defined in router Bldg1. The connection to Bldg2 is using a Layer2 switch with a routed link thru fiber. How I can transfer the vlan information from the other Bldg ?


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gdrandles Tue, 11/03/2009 - 10:12
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If both switches are Cisco and support VTP then you can setup Bldg1 switch as the server and Bldg 2 as the client. Connect the switches using a trunk port and put both switches in the same vtp domain and the vlans will propagate from the server to the client. Additions and removals of vlans will only be allowed from the server switch. If there are not a lot of vlans or you don't share vlans between buildings, it may be administratively easier to just manually create the vlans on each switch.

maria.melendez Tue, 11/03/2009 - 10:45
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Yes, both switches are Cisco and support VTP but the link between them will be thru a routed link not trunk port.

I guess that probably the best approach is not to share vlans. This connection is going to be temporary until we move completely to the Bldg2.


iyde Thu, 11/05/2009 - 11:21
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If it is a routed port then run vtp transparent at both sides, define the VLANs that you need locally at each side and the do routing between the two sides.

Be aware that you will not be able to have the same IP segment at both sides.

HTH, Ingolf

glen.grant Thu, 11/05/2009 - 11:26
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If it s just temporary, change the routed port on both sides to a SVI in a vlan on both sides then trunk all vlans across , routing will still work .


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