setting up data and voice vlan

Unanswered Question
Mar 12th, 2007

Hi Gurus,

We just finished setting up a small office network. Our ISP will supply the phone system however they want that we reconfigure network for a vlan to separate the data and voice lines. We would like to start a separate data/voice vlan for LAN and Wireless.

We have a 851W router and two 2950 Cat switches and the phones would be Nortel BMC/ip phones. Our DHCP and DNS are set up on

a domain server/domain controller. We are newbies to vlans and ip phones.

We would like to know what is the best practice to set up the data and voice vlans. Any configuration examples are welcome especially with Nortel phone system to us get started. We have general idea on how the vlan work but we have no confidence in configuring such as assigning ip addresses to its corresponding ports.



I have this problem too.
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jason-calbert_2 Mon, 03/12/2007 - 13:59

on the 851 router you will need to setup sub interfaces. for example 0/1.10 0/1.20. You will also have to trunk these interfaces.

on the switches you will need to setup a normal data vlan lets say vlan 10 and also an auxillary vlan for voice lets say 20.

You will need to trunk down to the phones since they are Nortel and won't use CDP. There should be some way on the Nortel phones to choose which vlan to use. Please let me know if you have any questions.

Paolo Bevilacqua Mon, 03/12/2007 - 14:04

We you have't quite finished yet....

you need to setup the vlans, routing as necessary, the new DHCP pools on the server...

Are the PC daisy chained to the phones, or use independent ports ?

Unless you are determined technicians willing to learn and suffer, I suggest you contact a qualified cisco reseller that can help you in setting all this...

fwfhlconc Sat, 03/17/2007 - 10:08

Thanks guys.

Got something from you advice however

the 851w doesn't support multiple vlans.

I had everything set up on the swicthes

but got this problem with the 851w.



Paolo Bevilacqua Sat, 03/17/2007 - 14:35


I need to correct myself, you have an 850, not an 870, that according to the documentation, only supports "one 802.1q VLAN". In practice, you can't route between VLANs using this small router. I don't think this will make any issue in practice, with one VLAN everything should work fine anyway.


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