[c-nsp] Unable to connect VLAN traffic

[Justin Shore]

Johnny Ramirez wrote:
> We have layer 2 connectivity from our main office to an offsite facility where our servers reside. We are connected via fiber but is not a dedicated circuit.
>  
> Recently I  created a VLAN with same ID on both switches (main office and Offsite facility) . I trunked the port on both ends but not traffic passes on this VLAN. Obviously only VLAN 1 works. According to a consultant the provider of the fiber connection needs to turn "something" on  for us to be able to pass VLAN traffic other than VLAN 1's. What would be that "something", he does not even kow it himself. 
>  
> Can anybody shed any light on this?. We are urgently needing to have a separate VLAN for our VOIP traffic.

John,

Basically what this amounts to is that your transport provider is only 
accepting untagged Ethernet frames and thus only the one VLAN you 
previously used on your access interface.  You need the provider to 
accept tagged Ethernet frames so that tagged frames from each of your 
VLANs will be accepted for transport.  The provider may either dictate 
to you what VLAN IDs you must use.  They may use Q-in-Q (aka VLAN 
stacking) to assign their own tag in front of your tags.  This would 
give you the most flexibility and will keep you from having to work with 
them to allow future VLANs across the trunk.

Justin