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vlan trunk across isp network

Unanswered Question
Jun 25th, 2007
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Hello,


I'm trying to create a trunk across a link that my isp has given to me. I have a 3550 at both ends and I need to move across a couple of vlans.


I have tried this config and the trunk comes up, but I cannot transfer any ip information across it.


This is configured on both ends:


interface FastEthernet0/1

switchport access vlan 509

switchport trunk encapsulation dot1q

switchport trunk native vlan 509

switchport trunk allowed vlan 509

switchport mode trunk

end


Do I need to create a tunnel or something first?


Thanks,

Dan.

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Edison Ortiz Mon, 06/25/2007 - 18:26
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Do you have a SVI for VLAN 509 at each switch ?

If so, let's see the show ip int brief from each switch as well as show vlan and show trunk

danletkeman Mon, 06/25/2007 - 20:07
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switch1#sh ip interface brief

Interface IP-Address OK? Method Status Prot


Vlan509 10.50.9.24 YES manual up up


FastEthernet0/8 unassigned YES unset up up




switch2#sh ip interface brief

Interface IP-Address OK? Method Status Prot


Vlan509 10.50.9.3 YES manual up up


FastEthernet0/2 unassigned YES unset up up




switch1#sh interfaces trunk


Port Mode Encapsulation Status Native vlan

Fa0/8 on 802.1q trunking 509


Port Vlans allowed on trunk

Fa0/8 509


Port Vlans allowed and active in management domain

Fa0/8 509


Port Vlans in spanning tree forwarding state and not pruned

Fa0/8 509





switch2#sh interfaces trunk


Port Mode Encapsulation Status Native vlan

Fa0/2 on 802.1q trunking 509


Port Vlans allowed on trunk

Fa0/2 509


Port Vlans allowed and active in management domain

Fa0/2 509


Port Vlans in spanning tree forwarding state and not pruned

Fa0/2 509



The vlan exists on both switches when i type sh vlan


I have other trunk's setup on these switches to other locations on my own network. The only one that cannot transfer any traffic is the one over the isp link.

Edison Ortiz Tue, 06/26/2007 - 07:41
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I'm assuming you are unable to ping from site A to site B ?

Edison Ortiz Tue, 06/26/2007 - 10:56
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Did you verify with the ISP that 509 is the transit VLAN ?


Did you try creating an additional VLAN (say, 510) and make that the L3 VLAN (of course, you will have to allow that VLAN in the trunk as well).


danletkeman Wed, 06/27/2007 - 05:56
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Unfortunately I cannot rely on the isp in this situation. Is there a way I can create a tunnel or something of that sort?

Edison Ortiz Wed, 06/27/2007 - 07:34
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The ISP supplies the end-to-end connectivity here. If their L2 configuration is not done correctly, you won't be able to establish a L2 or L3 connection between these locations.



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