Hi,

I have reviewed the document and it is clear written.

Here are two nits commments:

In Section 5. RIB Extension YANG Model
1)
 OLD:
    description
       "This YANG module extends the RIB defined in the ietf-routing
        YANG module with additionalroute attributes.
NEW:
    description
       "This YANG module extends the RIB defined in the ietf-routing
        YANG module with additional route attributes.

2) grouping next-hop is defined but not used, is this intentional?

Thanks,
Bo Wu