Re: Switchport trunk allow ?

No. The first question to ask yourself is: what is the importance of Native Vlan? What is it supposed to do? In short ask yourself why am I specifying this vlans?

Once you answer this questions, you will know that the command you require under that interface is "swithp trunk native vlan 50". Since you changed your Native Vlan from 1 which by the way you cannot block. Another question you should ask is why did they / you change the native vlan from 1 to 50?

"tagged, untagged"

 Babatunde Sanda B.Sc (Acct.) CCNP, CCVP, CCNA(R,S,V), MCSA, N+, A+.
:: Sent from my Iphone. Apologies for errors and brevity. ::

On Oct 24, 2010, at 7:22 AM, Vincent Tay <vtay.75_at_gmail.com> wrote:

> Hi Paul,
>
> Thanks for the information.
>
> If we cannot prevent vlan 1 but we change the native vlan to vlan 50 for
> example, must i explicitly allow the native vlan 50 with the command
> switchport allow vlan 50, ..... etc? Thanks.
>
> Regards
> Vincent Tay
>
> On Sun, Oct 24, 2010 at 11:18 AM, Paul Negron <negron.paul_at_gmail.com> wrote:
>
>> I may be wrong but I thought you could not prevent Vlan 1. It has been a
>> long time since I messed with the switches though.
>>
>> Paul
>> --
>> Paul Negron
>> CCIE# 14856 CCSI# 22752
>> Senior Technical Instructor
>> www.micronicstraining.com
>>
>>
>>
>>> From: Dale Shaw <dale.shaw_at_gmail.com>
>>> Reply-To: Dale Shaw <dale.shaw_at_gmail.com>
>>> Date: Sun, 24 Oct 2010 14:05:46 +1100
>>> To: Vincent Tay <vtay.75_at_gmail.com>
>>> Cc: "Ccielab_at_groupstudy.com" <ccielab_at_groupstudy.com>
>>> Subject: Re: Switchport trunk allow ?
>>>
>>> Hi Vincent,
>>>
>>> On Sun, Oct 24, 2010 at 1:55 PM, Vincent Tay <vtay.75_at_gmail.com> wrote:
>>>>
>>>> If i use the command switchport trunk allow, do i have to include the
>> native
>>>> vlan "switchport trunk allow vlan1,.... if vlan 1 is a native vlan in
>> order
>>>> to bring the trunk up?
>>>
>>> Not in my experience, no -- the native VLAN does not need to be
>>> explicitly included in the list of VLAN IDs specified with "switchport
>>> trunk allowed vlan" command.
>>>
>>> From the command reference:
>>>
>>> "allowed vlan *vlan-list* // Set the list of allowed VLANs that can
>>> receive and send traffic on this interface in tagged format when in
>>> trunking mode"
>>>
>>> The keyword there being *tagged*.
>>>
>>> VLAN 1 is a special case but I'll leave it up to you to figure that one
>> out
>>> :-)
>>>
>>> cheers,
>>> Dale
>>>
>>>
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>
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Received on Sun Oct 24 2010 - 07:46:44 ART