[c-nsp] Question about VLAN Trunks

[Chris Knipe]

Hi,

Output below...
cs1.blv0.cpt.za#sh int fa8/5 switchport
Name: Fa8/5
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: down
Administrative Trunking Encapsulation: dot1q
Negotiation of Trunking: Off
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 105 (LAN-WORKSTATIONS)
Voice VLAN: 104 (LAN-VOICE)
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: 104,105
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL


Nothing seriously wrong that I can see...

-
Chris.


On Wed, Jul 20, 2011 at 2:03 PM, Mackinnon, Ian <Ian.Mackinnon at atos.net> wrote:
> What does a show interface fa8/5 switchport show
> It might be that the switchport mode trunk and switchport voice vlan
> commands are incompatible
>
> Have a look at
> http://cciepursuit.wordpress.com/2009/01/01/group-study-good-explanation
> -of-the-voice-vlan/
>
>> -----Original Message-----
>> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-
>> bounces at puck.nether.net] On Behalf Of Chris Knipe
>> Sent: 20 July 2011 12:45
>> To: cisco-nsp at puck.nether.net
>> Subject: [c-nsp] Question about VLAN Trunks
>>
>> Hi All,
>>
>> I have a good couple of 10/100 ports configured for non-Cisco VoIP and
>> during troubleshooting an issue yesterday, I noticed that our VLAN
> trunks are
>> not behaving as I expected.  All my ports are configured as
>> follows:
>>
>> interface FastEthernet8/5
>>  logging event link-status
>>  logging event spanning-tree status
>>  logging event bundle-status
>>  logging event trunk-status
>>  load-interval 30
>>  keepalive 30
>>  mls qos trust cos
>>  switchport
>>  switchport trunk encapsulation dot1q
>>  switchport trunk native vlan 105
>>  switchport trunk allowed vlan 104,105
>>  switchport mode trunk
>>  switchport nonegotiate
>>  switchport voice vlan 104
>>  power inline never
>>  storm-control broadcast level 85.00
>>  no cdp enable
>>  spanning-tree bpduguard enable
>>  spanning-tree link-type point-to-point
>>
>> When connecting a PC directly to the port and doing some tcpdumps, I
> see
>> traffic on the trunk port that falls outside of VLAN104 and 105...
>> Shouldn't the switchport allowed vlan only allow vlan 104 and 105 to
> pass via
>> the port?
>>
>> These are on Cisco 6500's with SUP II and MSFC II, IOS
>> c6sup22-jk2sv-mz.121-26.E6
>>
>> --
>>
>> Regards,
>> Chris Knipe
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>
>
>
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-- 

Regards,
Chris Knipe