RE: Fwd: Minutes / Notes

[Erik Nordmark <Erik.Nordmark@sun.com>]

> So, i guess that you need to carry the locator of the destination, since it
> is needed to forward the packet to the destination.
> I guess that you donīt need to carry the destination identifier in all
> packets.
> For the source endpoint information, i am not sure.
> I think that carrying the source identifier would make more sense, since it
> identifies the other endd of the communication. 

For the source part (locator vs. id) we need to understand how multicast
routing would work. Today it applies RPF to the source address and uses the
hierarchical structure of the source address to aggregate the information used
by the RPF. If the source identifiers are not aggregatable this will be an
issue.

> This would also allow to
> configure filters depending on the source identifier making things like
> renumbering easier. The first problem that i find with this option is that
> you cannot send error messages back to the source (since there is no locator
> of the source) when there is a problem and additional mechanisms are needed
> to perform reverse mapping in this situation.

The ability to return packets without much overhead, such as an ICMP error or
a  TCP SYN, might be important to avoid a class of DoS attacks om routers.
Having the source locator in the packet
means that an ICMP error can be generated without performing
any ID->locator mapping

  Erik