On Thu, Nov 7, 2013 at 5:45 PM, Fred Baker (fred) <[email protected]> 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 _______________________________________________ rtgwg mailing list [email protected] https://www.ietf.org/mailman/listinfo/rtgwg
