Migrating from ME3400E to ASR920 - Trunking + Switchport Interfaces

G'day all,

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We're currently beginning our replacement of our aging ME3400E's into ASR920's. I just wanted to run a few things by the brains trust to better understand configuration migration paths.

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From my understanding with classic L2 VLAN Switchports you move into a service instances and Bridge Domain Interfaces?

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E.g.

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if we are migrating from Me3400 config for a customer;

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interface fa0/1 description Customer 1 switchport access vlan 200 ! interface vlan 200 description Customer 1 ip vrf forwarding <vrf> ip address 1.1.1.1 255.255.255.248 

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To ASR 920 config;

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int gi 0/0/1 description Customer 1 no ip address service instance 1 ethernet encapsulation untagged bridge-domain 200 ! interface bdi200 description Customer 1 ip vrf forwarding <vrf> ip address 1.1.1.1 255.255.255.248 

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Would this be correct?

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Now from my understanding with the above EFP configuration we can utilise the same service instance ID on each interface as a service instance ID is unique only to an interface, changing the bridge-domain to ensure layer 2 separation?

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So if we add in customer 2 it would be as follows:

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From ME3400e;

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interface fa0/1 description Customer 2 switchport access vlan 300 ! interface vlan 300 description Customer 2 ip vrf forwarding <vrf> ip address 2.2.2.2 255.255.255.248 

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To ASR920;

int gi 0/0/1 description Customer 2 no ip address service instance 1 ethernet encapsulation untagged bridge-domain 300 ! interface bdi300 description Customer 2 ip vrf forwarding <vrf> ip address 2.2.2.2 255.255.255.248 

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Assuming I'm still on the right track here, moving onto Layer 3 services for customers.

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We also currently have customers with Layer 3 connections to our ME3400, we create an SVI for them and carry that edge VLAN back to our core on the same port channels. Example below:

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int fa0/10 descr Cust 3 Layer 3 connection no switchport ip vrf forwarding <vrf-cust-3> ip address 3.3.3.3 255.255.255.0 ! int vlan 400 descr customer 3 SVI back to core ip vrf forwarding <vrf-cust-3> ip address 10.10.10.5 255.255.255.0 

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What does the physical and SVI interface configuration become for an ASR920?

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Moving to the next step, now we have both a combination of Layer 2 customer links and Layer 3 customer links, we trunk all VLANs back to our core.

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We have a port-channel with two members currently, how are these configured?

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int po 1 ??? int te0/0/24 ??? int te0/0/25 ??? 

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I'm also open to adjusting our configuration if there are better ways of handling this that are much more scalable in future. The only consideration here is we don't typically control the other end of the customer links landing on our ME3400, so if major configuration changes are required we'd have to engage their carrier/the customer to implement them.