- and tell you about views of the Internet passed on from other neighbors
You can arrange to absolutely trust a given neighbor to be that neighbor, but until every BGP speaker in the world has that relationship, you can't trust the data that they pass on.
And every BGP speaker in the world has both direct controls (advertise this AS, don't advertise that AS) and influential controls (pretend that this AS is farther away than it is, prefer this AS here and not there because it's cheaper for us) that are both necessary and desirable, because money constrains what engineering can do.
- not controlled by you
- tell you about their own view of the Internet
- and tell you about views of the Internet passed on from other neighbors
You can arrange to absolutely trust a given neighbor to be that neighbor, but until every BGP speaker in the world has that relationship, you can't trust the data that they pass on.
And every BGP speaker in the world has both direct controls (advertise this AS, don't advertise that AS) and influential controls (pretend that this AS is farther away than it is, prefer this AS here and not there because it's cheaper for us) that are both necessary and desirable, because money constrains what engineering can do.