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obtaining IP address for voice and data

I don`t seem to obtain a straight answer from any data guys- I`m voice

How do I make vlans go to different scoops and different DHCP servers- data, voice

question 1

I have a switch which is connected to phones, on the port 1, I have configured a native data vlan and voice vlan- native 2, voice vlan 3-, port 2 have data native vlan 2 , voice vlan 3 . port 3 naive, voice vlan 4

Connected to this switch is the CCM using DHCP - test set up.On the DHCP I have set up 3 scoop VLAN 2 and VLAN 3 vlan 4 The first question is how can I make the vlan 2 go to scoop configured with and vlan 3 to go to scoop with IP address and VLAN 4 go to scoop vlan 4

The next question if the DHCP for data is else where , the switch has a IP helper address pointing to it so to turn the request into a routing request ? however as the site is running SRST I want to configure the SRST router with DHCP which will be used for the voice phones only all other devices will use the remote DHCP- how do I make the data device go to the remote DHCP and voice to use the SRST and choose the correct scoop

is it something like

interface vlan 2

ip helper xxxxx

interface vlan 2

interface vlan 3

interface vlan 4

many thanks


Re: obtaining IP address for voice and data

Hello Wayne,

Do you have two DHCP server in each of the VLAN's?

One of the major differences between routers and switches is as follows:

A) Routers do not forward broadcast traffic by default. Broadcast traffic will include DHCP request. If you need to target a DHCP server from a router, then we use ip helper-address command. BTW the DHCP server can be on another subnet ( or vlan ), in this instance.

B) Switches will forward (or replicate), broadcast traffic to all nodes through switch ports within the VLAN.

So you do not need the 'ip helper' command on a switch as long as a DHCP server lives on the same VLAN. There will be two separate DHCP requests that come into the switch from the IP phones connection. The first request will be from the IP phones itself and the second of course is from the host PC.

If you would like me to explain further please do not hesitate to come back to us.



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