Voice Vlan really required if only using a IP phone on the port.

[Michael Douville]

Hello There!

I have a fellow employee that sets up his phone port when the phone is the ONLY device as follows:

conf t

switchport access vlan 4

we use vlan 4 as the voice vlan.  However when I set it up I always do the following.

conf t

switchport voice vlan 4

I know mine has the advantage that you can add the a PC and another vlan ( or use the default vlan) without much configuration change.  But is it really OK to configure it the way he has?  I have not been able to verify this.  Googled and have not found much information yet.

Completed my CCNA and Part of my CCNP.  Never taken the Voice cert so I'm not as up on it.

Thanks in advance for the help!

Mike

[pwwiddicombe]

As you say, if you simply set up the port as access vlan 4, then if a PC is connected downstream from the phone (or replacing the phone), then it will be in vlan4, which may have undesired consequences in that situation.  Setting up access and voice vlan means you would probably have less issues down the road when things change.

[Richard Bradfield · Accepted solution]

It is best practice to setup both data and voice ports on the access ports of the  switch if you use both, then over time when things get connected to different ports, devices will be on the correct vlan.

[devils_advocate · Accepted solution]

Like others have said, its best practice to separate them but on small networks I have seen plenty of people not bother with a voice vlan.

If its only ever going to be a phone plugging in then I am not aware of any downsides to leaving this in the data Vlan, as long as this Vlan is technically used for 'Voice Traffic'.

As Richard pointed out, for futureproofing the network its good practice to configure them with both as it makes it easier if you decide to change plans moving forward and do want to daisy chain a PC off the phones. 

[Michael Douville]

Thanks for the responses, you  guys are awesome in responding so quickly!

So we are both correct in a way, but less issues in the long run if set as a voice port.   Seems we are always learning, lol.

Thanks again!

Mike