[c-nsp] trunk over isp's private vlan

[Jeff Fitzwater]

Dan look at the attached doc and see if it might help..

http://www.cisco.com/univercd/cc/td/doc/product/lan/ 
c3550/12113ea1/3550scg/swtunnel.htp

Jeff Fitzwater
OIT Network Systems
Princeton University


On Jun 24, 2007, at 1:56 PM, Dan wrote:

> I'm a bit confused.  The doc says that trunking is not allowed on a
> l2protocol-tunnel port.  How can I have multiple vlan's going across a
> link if I can't trunk?
>
> Thanks,
> Dan.
>
> Jeff Fitzwater wrote:
>> The config you have, does not tag any vlan even though you have
>> trunking enabled.  You are sending vlan 509 as native with no 802.1Q
>> taging.
>>
>> You could either set native to some other vlan or look into  vlan
>> tunneling, which double tags the packet so that it can traverse ISP
>> that may be using your  VLANs .  Is the other end set up for  
>> trunking?
>>
>> It would be best if you looked at the CISCO doc on the Tunneling.  I
>> think the 3550 supports it.  Also if the native vlans are different,
>> and that is your intent, then you must disable CDP and ST or P for
>> that vlan or the link will not come come up.  Look at log for PVST
>> ERRORS.
>>
>>
>> Jeff Fitzwater
>> OIT Network Systems
>> Princeton University
>>
>> On Jun 23, 2007, at 2:38 PM, Dan wrote:
>>
>>> Hello,
>>>
>>> I need to create a trunk between two of my 3550 switches which are
>>> interconnected over my isp's network.  I can establish the trunk  
>>> but I
>>> cannot get any ip information across the trunk.  I have many other
>>> trunks setup but this is the only one I have across someone else's
>>> network.  Here is my config, its the same for both sides:
>>>
>>> interface Vlan509
>>>  ip address 10.9.9.24 255.255.255.0
>>>  ip ospf cost 50
>>> end
>>>
>>> interface FastEthernet0/8
>>>  switchport trunk encapsulation dot1q
>>>  switchport trunk native vlan 509
>>>  switchport trunk allowed vlan 509
>>>  switchport mode trunk
>>>  no cdp enable
>>>  spanning-tree portfast
>>> end
>>>
>>> sh interfaces trunk shows the vlan in spanning tree forwarding state
>>>
>>> This is a redundant link that I have setup that is why the ospf cost
>>> is 50
>>>
>>> What could be wrong?
>>>
>>> Thanks,
>>> Dan.
>>>
>>>
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>
>
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