Re: [RFC net-next 1/2] net: allow user to set IPv6 nexthop for IPv4 route

Sowmini Varadhan
2015-03-27T13:23:58Z

On Thu, Mar 26, 2015 at 5:05 PM, Andy Gospodarek
<gospo@cumulusnetworks.com> wrote:
> This adds kernel infrastructure to allow userspace (read: routing protocols) to
> support adding IPv6 next-hops to IPv4 routes. This is essentially added to
> support a feature of MP-BGP outlined in RFC-5549.
>
> Thise does not encompass all that is needed to support RFC-5549, but this
> demonstrates the netlink infrastructure needed to correctly enable the kernel
> infrastructure that would support this RFC. For more informtion the full RFC
> is here: http://www.ietf.org/rfc/rfc5549.txt.

Is there some impact to redirect behavior? RFC 5549 does not seem to
discuss it at all, but the firsthop would be processing (and
potentially sending)
an icmp redirect to the host. I dont think there is a good way to construct
this, either with icmpv4 or icmpv6, and maybe some checks are needed to
not even try, when the IP mix-match is encountered.

--Sowmini