Comment 2 for bug 1562067

@Carl :
I agree with your proposal, the code via subnet would be difficult.
However, I think instead of changing the router-port-list, we can create a network-router-list CLI, which will do the same thing, but instead of modifying the currently working code of router-port-list, provide a new CLI to do the same work.

So if a user provides a network to the network-router-list, it will show the information of all the routers connected to the network.
It will take care of the deduplication as well , so that the user does not require any processing to be done at his end.

let me know if you agree with this solution in the following patch.