At 09:53 01/09/00 +0200, Sascha E. Pollok wrote:
Somewhere in Basham Halabi's "Internet Routing Architectures" (Cisco Press) he mentions that two different origins for a prefix is an "illegal configuration". Unfortunately I just can't find the exact phrase in the book.
Yes, I remember seeing it in there. I'm kinda curious why a "generally should not" in an RFC becomes a "must not" in the real world though.
Anyway, I am sure that announcing the same prefix under 2 different origins should work although I never did something like this.
It obviously does - I counted around 600 today.
Let's further discuss this at ripe-37.
And like RIPE-210/route-flap dampening, maybe we can come up with some recommendation in writing which says "must not", if that is the right thing to do. Ofcourse, as to the original topic, it is perfectly possible to set up a net to multihome between two different ISPs, using a private AS, and not cause any issue with inconsistent origin ASes... Nor cause too much problem with routing a subprefix of another LIR's PA block. best wishes, philip --