Re: 2 Voice vlan questions: 1) Testing the config 2) Dot1p

From: Carlos G Mendioroz (tron@huapi.ba.ar)
Date: Mon Dec 08 2008 - 20:05:33 ARST

Hobbs,
VLAN 0 is not a VLAN, is just a filler for the VLAN ID that is not being
used. The port is an access port, the VLAN is whichever you assigned to it.

Traffic being sent to the phone is not tagged.

-Carlos

Hobbs @ 8/12/2008 19:41 -0200 dixit:
> Thank you Alexei.
>
> But how does traffic get TO or FROM this port with vlan 0 tagged?
> How does it learn MAC addresses on this vlan? Does it send it out all trunk
> ports?
> "Show interface trunk" does not show vlan 0 as allowed or active...
>
>
> On Mon, Dec 8, 2008 at 2:17 PM, Alexei Monastyrnyi <alexeim73@gmail.com>wrote:
>
>> Hobbs,
>> as per 3550/3560 configuration guide:
>>
>> "Instruct the switch port to use 802.1P priority tagging for voice traffic
>> and to use the default native VLAN (VLAN 0) to carry all traffic. By
>> default, the Cisco IP phone forwards the voice traffic with an 802.1P
>> priority of 5."
>>
>> HTH
>>
>> A.
>>
>>
>> Hobbs wrote:
>>
>>> Disregard the first question...I had a freakin' ACL on R2. So the test is
>>> GOOD.
>>>
>>> My question number 2 still remains...
>>>
>>> thank you,
>>>
>>>
>>> On Mon, Dec 8, 2008 at 2:04 PM, Hobbs <deadheadblues@gmail.com> wrote:
>>>
>>>
>>>
>>>> Hello my friends,
>>>>
>>>> I have 2 questions regarding voice vlans:
>>>>
>>>> 1) Is it possible to test voice vlan by using subinterface and dot1q
>>>> encapsulation on a router port:
>>>>
>>>> R1----SW1----SW2----R2
>>>>
>>>> R1 has a subinterface with "encap dot1q 2".
>>>> SW1 has "voice vlan 2" on port to R1.
>>>> Link SW1-SW2 is a trunk with all VLANs allowed.
>>>> R2 is in vlan 2.
>>>>
>>>> R1's config:
>>>>
>>>> interface Ethernet0/0
>>>> !
>>>> interface Ethernet0/0.2
>>>> encapsulation dot1Q 2
>>>> ip address 139.1.2.101 255.255.255.0
>>>>
>>>> SW1:
>>>>
>>>> interface FastEthernet0/1
>>>> switchport access vlan 11
>>>> switchport mode access
>>>> switchport voice vlan 2
>>>> spanning-tree portfast
>>>>
>>>> Should R1 be able to ping R2 at 139.1.2.2 ? As of right now, I am not
>>>> able
>>>> to. When I debug icmp, packets from R2 reach R1, but packets from R1
>>>> never
>>>> get to R2. Looks like SW1 is not sending packets from the voice vlan over
>>>> its trunk to SW2.
>>>>
>>>> 2) What vlan # is used when you configure "switchport voice vlan dot1p"?
>>>> How does the switch know when to send traffic TO this port on the voice
>>>> vlan.
>>>>
>>>> thank you,
>>>>
>>>>
>>>
>>> Blogs and organic groups at http://www.ccie.net
>>>
>>> _______________________________________________________________________
>>> Subscription information may be found at:
>>> http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
>
>
>
>
>
> 

-- 
Carlos G Mendioroz  <tron@huapi.ba.ar>  LW7 EQI  Argentina

Blogs and organic groups at http://www.ccie.net

This archive was generated by hypermail 2.1.4 : Thu Jan 01 2009 - 12:53:08 ARST