On Oct 7, 2008, at 8:09 AM, Matt Lepinski wrote:
2) With regards to format, there was discussion in March in Philidelphia which led to the addition of the max-length field. At that time, the question was raised as to whether there should also be a min-length field and at the time there seemed to be no operator requirement for such a field. In particular, to justify a min-length field one would need a use-case where a registered holder of IP resources wishes to give an AS permission to advertise many long prefixes, but expressly forbid the AS from advertising the aggregate prefix. Such a use-case seems unlikely because in most cases advertising the aggregate prefix does no harm (and indeed will be ignored in the presence of advertisements for longer prefixes) although I could be missing something.
Matt, Catching up on old email (rereading while looking at I-D changes) One trivial comment here.. If two ASes announce the same aggregate (prefix/len) it can certainly do harm, as more specifics may be suppressed and routing would simply select the preferred AS based on AS_PATH or other selection criteria. Route hijacks that are no more specific than the legit route occur frequently, and cause considerable pain to the prefix holder. I'm not making a case for minLength, just sharing an observation. -danny _______________________________________________ sidr mailing list [email protected] https://www.ietf.org/mailman/listinfo/sidr
