BGP4 COMMUNITY attribute

> What is the general concensus about passing communities in the


i could see a reason for a subscriber passing communities
through a mid-level provider to a top-level provider. but i'm
not sure if it makes sense [yet] for top-levels to pass
communities between themselves

> > > 1. Is COMMUNITY a transitive attribute only between me and my


> > > upstream supplier or
> > > is it being propagated further into Internet (so I can influence how
> > > somebody ,say, 5 AS hops
> > > away from me sees my routes) ?
> >
> >the attribute is defined as transitive (i.e., once associated
> >with a route it *stays* associated with the route). however, in
> Unless an intermediate provider deliberately changes the value, as
> opposed to appending to it.

these values aren't an end-to-end thing .. it's simply a
way for providers to more easily facilitate routing policies.
your comment implies somebody being a bad guy...

Actually, I hadn't necessarily meant to imply "being a bad guy".
The comment was meant to show that the "intermediate" ISP has this
kind of control over the attribute. In any case, if the decision
about whether or not to pass on an attribute (or to modify it) was
part of the intermediate ISP's policy, whether or not he/she is a
bad guy would depend on varying points of view.