> They'd need multiple ASNs for each of these network islands then, though
No they wouldn’t. They could connect to local transit/IXs in each region and just advertise the regional networks.
No they wouldn’t. They could connect to local transit/IXs in each region and just advertise the regional networks.
I then have 2.2.3.0/24 advertised out of Frankfurt with the same AS. Again I have transit. I can reach 1.1.1.1.
How does a packet from 2.2.2.1 reach 2.2.3.1 -— 2.2.3.0 won’t be advertised by the transit to me in NY as it thinks I’ve already got the route, after all it originated from my AS.
The transit may not send you your routes with your ASN due to how its policies are configured, but that is configurable, not protocol-level issue.
And most BGP implementations have knobs to disable the loop check, so on your side you could just disable it.
That said, you can often still communicate between two NATs using various traversal techniques, although that's generally less likely for carrier-grade NATs, so NAT traversal solutions usually need relays as a fallback anyway.
But basic routing entity in BGP is still prefix/route, and different routes of one AS can be announced in different ways.
This is actually what they do when you enable Global Accelerator which is a paid feature. In GCP they have similar concept called “Premium Tier”