On 2 Mar 2005, at 22:30, David Schwartz wrote:
Please just clarify the following point: do you intend to advertise paths containing AS numbers belonging to other entities on the public Internet without the permission of the owners of those AS numbers? You admit that you don't know what the consequences of this injection will be.
Prepending announcements with remote AS numbers has been a well-known technique for preventing prefixes from propagating to particular ASes for a long time.
And therefore such use would not be considered experimental. We are talking about experimenting with routes that falsely claim to have passed through another autonymous system.
The AS_PATH attribute is a loop detection mechanism, and a determinant in path selection. What other magic is there in it that requires such careful consideration? Why should anybody need to get permission from remote operators before deciding what attributes to include in their own advertisements?
Every piece of BGP documentation I have ever seen says that this attribute documents the ASes that the route has actually passed through.
Do I need to get permission from Sprint before I include 1239:100 as a community-string attribute on my own advertisement, too?
You certainly need their permission before you can advertise routes that falsely came to have passed through their network! And yes, I would argue that you do need permission to attach someone else's community string to your routes and that it would be considered at least terribly bad manners to use undocumented community strings from other people's ASes. (Documentation, of course, equates to permission.)
It seems to me that there are enough issues with this type of experimentation *with* the permission of the AS numbers you plan to use. But the ethical issues with using them without such permission seems to me to be insurmountable.
The ethical issues seem to be non-existent, to my way of thinking, and hence trivial to surmount :-)
I'm curious where you would draw the line then. And I'm curious what you think is the point of registering AS numbers at all, if it's okay to use other people's without their permission. DS