Re: [v6ops] [homenet] Tsinghua work on source/destination routing

> I'm seeing plenty of packets from link-local sources to global
destinations
> .....
> 2) routers on the Internet do forward such packets (violating the rule
mentioned above).
> Fixing #2 actually requires making forwarding decision based on src
> and dst (which is not happening now).

To fix the above issue, wouldn't address scope checking be enough, rather
than the [src,dst] based routing
discussed ?

On Thu, Nov 7, 2013 at 8:58 AM, Jen Linkova <furry13@gmail.com> wrote:

> On Thu, Nov 7, 2013 at 5:45 PM, Fred Baker (fred) <fred@cisco.com> wrote:
> > Examples of use cases are generally around multi-prefix campus networks.
> There is a security use case that could be of value; at IETF 87, George
> Michaelson of APNIC reported on ULAs seen in his darknet. The short report
> is that he sees a fair bit of traffic with a ULA source address on the
> backbone. An interesting potential use of source/destination routing would
> counter that, and perhaps mitigate the need for ISP BCP 38 if generally
> deployed; in a case where a network is using a ULA and a global prefix
> (e.g., is not multihomed but has two prefixes, one of which is intended to
> only be used within its network), the default route to the network egress
> would use the global prefix as a source, and as a result traffic sent
> outside the network with a ULA source prefix would in effect have no route.
> The network could literally only emit traffic from its correct prefix.
>
> Looks like we (finally) have a chance to enforce the requirement from
> RFC4007, Section9:
>
> "If transmitting the packet on the chosen next-hop interface
> would cause the packet to leave the zone of the source
> address, i.e.,
> cross a zone boundary of the scope of the
> source address, then the packet is discarded. "
>
> I'm seeing plenty of packets from link-local sources to global
> destinations which means that:
> 1) there are hosts with broken default address selection
> AND
> 2) routers on the Internet do forward such packets (violating the rule
> mentioned above).
> Fixing #2 actually requires making forwarding decision based on src
> and dst (which is not happening now).
>
> More data (sorry, shameless plug :))
> https://ripe67.ripe.net/presentations/288-Jen_RIPE67.pdf
>
> --
> SY, Jen Linkova aka Furry
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