routing policies
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... between ASes that is subject to routing policies. Consider the case
of two ASes, X and Y exchanging routing information ...
... group of prefixes there
are various different routing policies. Without exception, an AS must
have only one routing policy ...
... prefixes. This situa-
tion is rare and should almost never happen. Very few stub sites
require different routing policies than their parents. Because
the AS is the unit of policy, however, this sometimes occurs.
...
... ASes containing
them. This is, of course, a trade off -- it will not always be
possible to implement all desired routing policies.
...