The trunk will come up fine, but you won't have IP connectivity between the 2 devices on the VLANs/subnets you are expecting because the 2 native VLANs are being bridged.  Do some research on how dot1q trunks work and you should be able to figure it out. 
On Dec 7, 2011, at 11:40 PM, CCIE KID <eliteccie_at_gmail.com> wrote:
> Hi fellas,
> 
> I tested a scenario where the Native vlan differs from the router port to
> the switch port. I understood that if the NAtive vlan mismatches on a trunk
> port , then appropriate trunking wont be formed.
> But when i connect my router to a switch and in the router subinterface . I
> am having a native vlan of 20 and in the switch port it is having a native
> vlan of 10 , but still the trunk is forming perfectly
> 
> Can someone correct me
>            fa0/1.1                                  fa0/1
> Router1-----------------------------------------------Switch 1
> 
> Router 1
> 
> inter fa 0/1.1
> encap dot1q 20 native
> ip add 10.1.1.1 255.255.255.0
> no sh
> 
> 
> Switch 1
> 
> int fa 0/1
> enc dot1q 10 native
> swi trunk enc dot
> swi mo trunk
> no sh
> 
> 
> But s
> 
> -- 
> With Warmest Regards,
> 
> CCIE KID
> CCIE#29992 (Security)
> 
> 
> Blogs and organic groups at http://www.ccie.net
> 
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Received on Thu Dec 08 2011 - 05:25:17 ART
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