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

On Thu, Nov 7, 2013 at 7:40 PM, Hermin Anggawijaya
<hermin.anggawijaya@gmail.com> wrote:
>> 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 ?

My point is that to do verify the scope, the router need to check
*source* address while making forwarding decision.
It looks like it is not happening now but it might get changed by
[src, dst] based routing.

> 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
>> _______________________________________________
>> v6ops mailing list
>> v6ops@ietf.org
>> https://www.ietf.org/mailman/listinfo/v6ops
>
>

-- 
SY, Jen Linkova aka Furry