Todd Underwood wrote:
you're probably right (as usual). but it seems that if you delay acceptance of announcements with novel origination patterns, you don't harm very many legitimate uses. in particular, ASes changing upstreams won't be harmed at all. people moving their prefix to a new ISP will have a fixed delay in getting their announcement propagated, sure. but they already have this delay now.
they tell the new ISP: 'announce my prefix' and the new ISP says 'prove it's yours'. they do that for a couple of emails. then the new ISP asks it's upstreams to accept that announcement. that takes a little while (ranging from 4 to 72 hours in my recent experience).
This is great for the planned changes, but real-time changes to respond to Internet dynamics won't work well with such delays. If you are multi-homed to provide a backup, you would like for it to respond more quickly than 4-72 hours, I'll bet. So if you have PI space but not your own AS, your backup route would look like a novel origination, but you sure wouldn't want it delayed. How common are such cases? Should the solutions cover them also? Should there be special procedures to deal with special cases? Etc. --Sandy