Is it permissible to advertise number resources allocated by one RIR to a ISP in a region governed by a different RIR? Practical?

Wed Feb 9 20:59:31 UTC 2011

Is it permissible, from a policy perspective, for a multi-homed end user
to announce the numbering resource allocation received from one RIR (for
discussion purposes, let's say ARIN) to upstream service providers in a
different region (for example, in the RIPE region)?

Is it feasible from a practical perspective?

I've looked through IANA and ARIN policy and can't find anything which
covers such a scenario.  I have seen some things about transferring
number resources from one RIR to another RIR, which is similar, but not
exactly the same.

Rationale:  

Suppose you are a large global enterprise, truly globalized in practice,
not in mere name, and performance concerns aside, you provide failover
for Internet access of enterprise users in one region by failing over to
internet access in a different region.  Since you probably are using
10/8 addressing within your network and you NAT the private IPv4
addresses to a public IPv4 address before sending the traffic on.., so
this works.   Given lack of NAT66, and the best practice IPv6 numbering
which is purported to use globally routable IPv6 addresses within your
enterprise network, the achievable way to accomplish the same use
possible today in IPv4 would seem to be to advertise the IPv6 addressing
from one RIR to a ISP in a region governed by a different RIR (or LIR). 