A flat network client is moving to new a Data center(DC). currently a non-cisco shop. Old and new DC will be connected via ISP layer 2 gig link. Client wants to move servers to the new DC on the legacy /16 ip space and wants the flexibility to move to a new segmented IP scheme on their own leisure.
i want to configure the ISP gig link as trunk carrying legacy (untaggged)vlan and a new vlan which would be used to route b/w new ip space and legacy ip space.
Provider has assigned two vlans to client vlan A and Vlan B.
I donot want to use vlan 1 at the new DC as a native vlan for the Trunk as it is bad practice to use VLAN 1 and i also do not want to associate in the new enviornment all flat-n/w-/16 traffic to vlan 1.
so i would like to create a trunk as follows:
New-DC[vlan-10 with Vlan 18 as native]------old-DC[vlan 10 with vlan 1 as native]
new DC
int vlan 10
192.168.1.1/30 advertised in ospf
old DC
int vlan 10
192.168.1.2/30 advertised in ospf
my first question is that would the trunk work with different native vlans. cdp carries the native vlan information however i am not sure if cdp would work as the switches in the old DC are non-cisco and i would also disable it on the cisco switch in the new DC.
My reasoning here is that clients flat n/w traffic is untagged today and would be carried in the native vlan ( which by default should be vlan 1) and should be able to communicate with other side native vlan which is non-routable and not vlan1.
My second question is that the ISP has assigned us two vlans and one of them is called primary which i think means native vlan. i would have to put a switch in between to change the native vlan from vlan 1 to Vlan A or is there another way with out putting a switch in between.
i know that that each trunk could have a different native vlan as it is local to the link and so for each trunk link a vlan which is used as native is sent across as untagged.
