Cisco Catalyst – Auto Voice VLAN on Catalyst 2960X

ciscocisco-catalystswitchvlanvoice

I am looking to reproduce a configuration that I have quite easily achieved on the Cisco Small Business Series SG500 family of switches. The configuration is for Auto Voice VLAN, triggered by CDP and/or LLDP, which results in dynamic interface configuration for a compatible device (i.e. Cisco phone) such that said interface sets the appropriate voice VLAN, native VLAN, and DSCP and CoS Values (46 and 5 respectively) are set for traffic on the Voice VLAN.

The resulting behavior is a compatible phone can be plugged into a port and will operate in the Voice VLAN while a computer connected to the phones switch port will enter the native VLAN. Again, voice traffic has DSCP/CoS values set as mentioned above.

I am comfortable with basic configuration of the Catalyst and have a CCNA in Routing and Switching…which does not cover these topics. From my research I gather that there are at least two separate components to achieving this configuration:

Configuration of the Voice VLAN: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-0_2_EX/vlan/configuration_guide/b_vlan_152ex_2960-x_cg/b_vlan_152ex_2960-x_cg_chapter_0110.html
Configuration of Auto Smartport: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-0_2_EX/autosmartports/configuration_guide/iosaspcg2960X/configure.html

By coupling these concepts together, should I be able to craft a configuration that achieves my objectives?

Is there anything else I should consider?

Best Answer

This is done all the time. Under a switch interface, you simply define a voice VLAN with the switchport voice vlan command. Something like this:

interface range GigabitEthernet1/0/1
 switchport access vlan 10
 switchport voice vlan 110
 switchport mode access
 no shutdown
!

The switchport access vlan command defines the data VLAN, and the switchport voice vlan command defines the voice VLAN. With Cisco phones, CDP will negotiate a trunk (the phone acts as a switch), or if there is no phone, then the interfaces acts as an access interface. You can enable LLDP on the interface for non-Cisco phones:

lldp run
!
interface range GigabitEthernet1/0/1
 switchport access vlan 10
 switchport voice vlan 110
 switchport mode access
 lldp transmit
 lldp receive
 no shutdown
!

Related Solutions

Vlan – Setting up PIM Sparse mode

My questions are:

Should we setup on our core network switch OSPF with a router ID of 1.1.1.1 and then not set any OSPF settings on any other switch?

OSPF is not necessary for this implementation.

Would PIM Sparse Mode only need to be enabled on the core switches or on all of the switches in the network?

Pim-SM needs to be enabled on each L3 interface on which you want to allow the multicast traffic. For example, if you wish to contain the traffic to Vlans 15 and 14, you would have to do the following on your core:

configure
ip multicast
ip igmp
ip pim sparse
interface vlan 14
ip igmp
ip pim
interface vlan 15
ip igmp
ip pim
exit

If you want the traffic to traverse all Vlans, then you will need the appropriate interface configuration under each Vlan. Your L2 switches will need IGMP snooping turned on (ideally on all interfaces via the global configuration).

configure
ip igmp snooping 
bridge multicast filtering

For a very basic multicast setup like this, these should be the only features that you would need.

Cisco – Voice VLAN information

First, a caveat: I'm not sure why you specified the following (emphasis mine),

Any suggestions for commands to specifically show the voice vlan assigned to a switch port without using too much reg-ex or seeking through the running configuration?

However, even the lengthiest reg-ex command in a Cisco device can be shortened by the alias command. In fact one of my frequently used aliases is to show the exact information you're looking for. Which I will include below.

Now, there are several ways to get the information you're looking for, and it depends on what exactly you know, and what you're trying to find.

If you know what the voice VLAN(s) is/are on that particular switch, and you're looking to find out what ports they're assigned to, you could simply issue the command:

show vlan id <voice-vlan-number>

This would give you a list of all ports utilizing that VLAN:

ATR4506-A1A-1#show vlan id 210 

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
210  ATRIUM-IP-PHONES                 active    Gi2/2, Gi2/3, Gi2/4, Gi2/5, Gi2/6,

If you know the port of interest (or want to see all ports) and just want to see which voice VLAN is in use on that port, you are looking for something like the following:

show interfaces switchport | include Name|Voice

I have this command aliased to svv (for show voice vlan) like so:

conf t
alias exec svv show interfaces switchport | include Name|Voice

This is the command I most frequently use to gather this information, and it gives the output:

ATR4506-A1A-1#svv                                      
Name: Te1/1
Voice VLAN: none
Name: Te1/2
Voice VLAN: none
Name: Gi2/2
Voice VLAN: 210 (ATRIUM-IP-PHONES)
Name: Gi2/3
Voice VLAN: 210 (ATRIUM-IP-PHONES)
Name: Gi2/4
Voice VLAN: 210 (ATRIUM-IP-PHONES)
Name: Gi2/5
Voice VLAN: 210 (ATRIUM-IP-PHONES)

Another alternative would be to filter the show run output if you need the exact interface names and switchport info (for scripting purposes for example):

show running-config | include interface GigabitEthernet|switchport voice vlan

This gives:

ATR4506-A1A-1#show running-config | include interface GigabitEthernet|switchport voice vlan 
interface GigabitEthernet1/3
interface GigabitEthernet1/4
interface GigabitEthernet1/5
interface GigabitEthernet1/6
interface GigabitEthernet2/1
interface GigabitEthernet2/2
 switchport voice vlan 210
interface GigabitEthernet2/3
 switchport voice vlan 210

Best Answer

Related Solutions

Vlan – Setting up PIM Sparse mode

Cisco – Voice VLAN information

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