Thanks for the hint, Yeah I missed the call to rt6_add_dflt_router while applying patch to master branch.
I am developer of SONiC OS (https://azure.github.io/SONiC/) in LinkedIn. We are planning to move to IPv6 only network and I realise that IPv6 needs capability to let administrator configure metric on default route learned via Router Advertisement in Linux. We support a fixed value 1024 today in Linux. Note for IPv4, administrator can configure metric on default route learned via DHCPv4. Kindly Review the fix, this feature is useful for IPv6 and Thanks Again.
