Re: How many legitimate cases when Origin AS in BGP announcement changed by another AS?

On Tue, Jan 04, 2011 at 04:38:19AM -0800, Akmal Shahbaz <akmal_shahbaz@yahoo.com> wrote a message of 443 lines which said:

I am looking for example routing policies when any AS receiving BGP advertisement changes Origin AS in BGP AS set attribute to remove the received AS number and puts its own AS number.[legitimate cases]

When the old origin AS was a private one? Today, with 32bits AS, everyone should have a public AS number but, in the real world, some people do BGP with private AS that the upstream provider has to change.