We recently upgraded some of our border routers to IOS-XE 16.6.3 code to take advantage of the inter-dc optimization features introduced for IWAN. Previously we were unable to path control our dc to dc traffic, so this seemed like a great improvement.
Our Cisco SE advised that we merge our dc-to-dc tunnels onto our main DMVPN head end, which provides hub-to-spoke functionality. We planned to use NHRP static mappings, which worked great. The tunnels formed and our routing protocols took over, advertising as they should. All sites were reachable, even dc-to-dc.
When I applied the
domain <blah> dci-path <blah> path-id <blah>
command to the DMVPN head end, it removed the previous
domain <blah> path <blah> path-id <blah>
command. It appears that only one of the domain commands can be applied to one tunnel interface at a time. My only thought at the moment is that perhaps we should have created a second DMVPN overlay tunnel for the dc-to-dc "dci-path" instead of trying to merge it with the existing hub-to-spoke "path" tunnel.
Has anyone else run into this while deploying the inter-dc optimization feature found here: