I want to create one SR tunnel between 4 FRR nodes where one node will be used as head-end node which will be used to push the label stack.SRGB in all these nodes will be same(10000-19999).I am going to use the loopback interface for node SID. I have few questions in this regard:

(1) How can I use one dummy interface as loopback in case of SR,I have tried using a dummy interface previously for vanilla OSPF and BGP,it works fine but in case of SR config,it complains:

not a loopback interface

(2)To provision the tunnel effectively,how can I use prefix SID for the connected interfaces.

I was using:

ip route x.x.x.x/mask <gateway> label as the node SID 

Here,how can I configure prefix SID for the prefixes other than the node prefix.

(3)How can I verify the tunnel in the data plane (e.g. ping works fine).

Any sample config in this regard will be helpful.

Thanks,

Shuvro