vlan trunk across isp network

danletkeman · ‎06-25-2007

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.

Edison Ortiz · ‎06-25-2007

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 · ‎06-25-2007

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.

sundar.palaniappan · ‎06-25-2007

Have a look at this document.

http://www.cisco.com/en/US/partner/products/hw/switches/ps646/products_configuration_guide_chapter09186a0080115937.html

HTH

Sundar

Edison Ortiz · ‎06-26-2007

I'm assuming you are unable to ping from site A to site B ?

danletkeman · ‎06-26-2007

That is correct.

Edison Ortiz · ‎06-26-2007

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 · ‎06-27-2007

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 · ‎06-27-2007

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.