I have a problem I cannot solve. If anyone is running confederations like

mine, I would appreciate some help

We have a 4-memberAS confederation, each with two IBGP peers. The

arrangement looks sort of like an octagon. the "r" is AS3 is an internal

hop, not a BGP peer.

Â Â Â _______ ______

Â Â > R-----R---r |

Â Â > / | | | |

Â Â >AS2 R | |AS3 R |

Â Â Â ----|-- ----|-

Â Â Â Â Â Â Â > >

Â Â Â ____|__ ____|_

Â Â >AS4 R | |AS1 R |

Â Â > \ | | / |

Â Â > R-------R |

Â Â Â ------- ------

The problem is this: How do you get BGP to choose the shortest "AS PATH",

since internal AS paths are ignored in selecting BGP routes? Right now,

to top router in AS4 will always choose a route through (2 3 1) instead of

(1), because it prefers "external" routes (even external confederation

routes) over internal routes.

So, when given a choice, the router on the distant side of the AS will

ALWAYS prefer the three-AS-hop path, because it is external. Is there a

way around this?!?

Avi Freedman suggested using a +1 metric when leaving each member-AS.

(Thanks Avi!) But it doesn't seem to help - perhaps I didn't do it right.

In fact, it doesn't look like the metrics are adjusted more than 1. for

example, from AS2, the lower router sees every route outside of AS2 as

having only metric 1! The top router in AS3 does not add 1 to the metrics

it readvertises to AS2.

I've been stewing over this problem for some time... I believe there is

some clue that I've missed. Any help would be greatly appreciated!

-Andy