For question 2, what I meant was that: Prior to issuing that command, according to the guide, we need to configure an IP address on the backplane port (e.g. G1/0 before issuing "service-module G1/0 session"). Instead of that, I want to configure an SVI or loopback on the router:
- For the SVI method, I could configure G1/0 and G1/1 as switchport mode trunk
- For loopback method, I could configure ip unnumbered lo0 on G1/0 and G1/1
Then I guess I would be able to issue service-module G1/0 (or G1/1) session. In case one backplane port has hardware problem, I can still access via the other one (since ISR G2 are EoS iirc). The ESM is used for aggregating all external connection (as a L2 switch), and connect them back to router via backplane, so I don't want any in-band management IP/routing on the switch.