[c-nsp] Connecting remote pops with EoMPLS?

[Peter Rathlev]

On Wed, 2010-03-17 at 19:05 +1100, Andy Saykao wrote:
> pc-1 -> switch-1 ->7606-1 <---> 7606-2 <-- switch-2 <-- pc-2
[...]
> Is it a matter of creating a SVI with the xconnect config on the
> 7606's - but how do I then get the switches to particpate in EoMPLS so
> that the devices connected to the switch ports on switch-1 and
> switch-2 appear as if they are in the same ethernet segment???

SVI based xconnect can only work with non LAN cards on the core facing
side. AFAIK the simplest (non redundant) way would be to transport the
relevant VLAN via a xconnected subif on a "MUX UNI" port on the 7600s.
If you need on (or both) of the 7606's to also L3 terminate the VLAN you
either need a non LAN card on the core-facing side or "the loop cable
trick".

Let's assume:

- Management VLAN for switch-1 and switch-2 are VLAN 50 in both ends.
- The "user" VLAN is VLAN 75 in both ends.

A skeleton configuration would be something like:

! *** switch-1 ***
interface GigabitEthernetX/Y
 description Uplink -> 7606-1
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 50,75
 switchport mode trunk
!

! *** 7606-1 ***
interface GigabitEthernetX/Y
 description Downlink -> switch-1
 switchport
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 50
 switchport mode trunk
!
interface GigabitEthernetX/Y.75
 description EoMPLS subif
 encapsulation dot1q 75
 xconnect <7606-2 IP> <VC ID> encapsulation mpls
!

and the mirrored configuration:

! *** 7606-2 ***
interface GigabitEthernetX/Y
 description Downlink -> switch-2
 switchport
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 50
 switchport mode trunk
!
interface GigabitEthernetX/Y.75
 description EoMPLS
 encapsulation dot1q 75
 xconnect <7606-1 IP> <VC ID> encapsulation mpls
!

! *** switch-2 ***
interface GigabitEthernetX/Y
 description Uplink -> 7606-2
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 50,75
 switchport mode trunk
!

I'm not sure how MST works across an EoMPLS VLAN, but a test setup
should be rather easy to do. If there's any way to block STP (and you
don't need any redundancy) the would probably be preferable.

-- 
Peter