[c-nsp] Upgrading older 7600 with an ASR1000 router.. Questions..

[James Jun]

On Wed, Dec 18, 2019 at 08:28:18PM -0500, Howard Leadmon wrote:
> 
> ??So enter the ASR1000 and I thought great, this is a simple change as I 
> should just be able to copy most of my 7600 configs across into the ASR 
> and life will be good.???? The I went to setup a trunked port to bring the 
> existing equipment into the new ASR.???? Surprise, unlike the old 7600 
> there is no turning a port in the ASR into a switchport, or not that I 
> can find, so it looks very much like it's an L3 device for the most 
> part.???? Well that sure blows up all the vlan interfaces/trunks that were 
> in the 7600 that will not transfer into the ASR.

Starting with the "real" (real as in... SR/Router BU) product side of 7600
(that will be ES and ES+ cards; Trident/EZchip NP I believe? mounted on top
of typical 6500 DFC architecture) and onward, you now have to use Ethernet
service instances to define layer-2 services on a port.

So ASR1K follows the same configuration syntax that was introduced with 
7600 ES cards, if I recall correctly.

As an example, let say you have a Te0/0/1 going to an L2 service provider as
an NNI interface.  Vlan 10 is layer-3 interface for IP routed connection
terminating locally on the router for a customer DIA connection; and Vlan 11 
is a layer-2 vlan you're pointing to the customer for a Layer-2 extension
that goes out via another port (lets call it GigabitEthernet0/0/3).
You would configure the services like this:

!
interface Te0/0/1
 description NNI to SP
 mtu 9216
 service instance 11 ethernet
  description (L2) vlan11 for 1Gbps to Customer B layer-2 extension
  encapsulation dot1q 11
  rewrite ingress tag pop 1 symmetric
  service-policy output shape-1g
  bridge-domain 11
 !
!
interface Te0/0/1.10
 description (L3) for 100Mbps DIA to Customer A
 encapsulation dot1q 10
 ip address x.x.x.x 255.255.255.252
 ip mtu 1500
 service-policy output shape-100m
!
interface Gi0/0/3
 description (L2) vlan11 UNI for Customer B layer-2 extension
 mtu 9216
 service instance 1 ethernet
  encapsulation untagged
  bridge-domain 11
!
!! optional: if you are providing pseudo-wire style service and do not want
!! to learn MACs on the layer-2 extension customer (bridge-domain 11):
bridge-domain 11
 no mac learning
!


Note that on newer IOS XE platforms, instead of using bridge-domain w/ MAC
learning disabled, you can use proper L2 vpn xconnect contexts, like this,
which will naturally stitch two interfaces together as a cross connect:

!
l2vpn xconnect context bd11_customer_B
 interwork vlan
 member Te0/0/1 service-instance 11
 member Gi0/0/3 service-instance 1
!
!! and you'd no longer need to define 'bridge-domain' commands


For more information, refer to 
 https://www.cisco.com/c/en/us/td/docs/routers/asr1000/configuration/guide/chassis/ce-xe-3s-asr1000-book/ce-trunk-efp.html
 https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/cether/configuration/xe-3s/ce-xe-3s-book/ce-ether-vc-infra-xe.html
 or Google search "ASR 1000 EFP" 


Hope this helps,
James