RE: ISP Policies

["Michel Py" <michel () arneill-py sacramento ca us>]

> Tulip Rasputin wrote:
> That's why i explicitly asked for some "social/political/etc."
> reasons where an ISP may not want his traffic to traverse some
> particular AS number(s). Something which is beyond BGP to
> determine as of now ! :-)

FWIW, this is exactly how I understood the question. It's all about
"non-BGP" issues.

> I believe with the responses that i received both on the list
> and offline, that it is indeed quite normal for ISPs to filter
> routes based on the AS Paths for 'other' reasons. Reasons,
> quite beyond BGP as a protocol to handle! And this can happen,
> when an ISP doesnt want its traffic to traverse some AS(es).

I'm not sure I agree with "normal", but it is common practice indeed, a
significant part being in a <cough> grey <cough> area, and notice that
nobody dared to post the reasons on the ML. Trying to stay
intellectually honest, there are "good" and "bad" reasons for it. 

Using my well-known politically incorrect bluntness, I would say this
(words borrowed from several people) (disclaimer #2: this is somehow
exaggerated, but here it is anyway):
God has given men a brain and a penis, but not enough blood to operate
both of them at the same time. Although there are exceptions, when the
blood flows to the brain, men use BGP; when the blood flows to the
penis, men manipulate the AS_PATH and/or create route-maps :-D

Michel.