AS10662 NORFOLK-SOUTHERN

NORFOLK-SOUTHERN is Norfolk Southern Corporation, one of the major North American Class I freight railroads, operating a network of roughly 19,000 route miles across the eastern United States from its headquarters in Atlanta, Georgia. This ASN carries the railroad's corporate network.

What it's used for

This is an enterprise end-site, not a provider. The AS announces two IPv4 prefixes, the legacy 167.121.0.0/16 and a more-specific 167.121.65.0/24 carved out of it, totalling 65,536 addresses. There is no IPv6, and RIS sees two observed neighbours.

The contrast between those two numbers is the point of the card. A /16 is a large block by any measure, but two neighbours says unambiguously that nothing wholesale is happening: the railroad buys transit from a small number of upstreams and announces its own space, and it carries traffic for no one else. A carrier holding 65,536 addresses would show hundreds or thousands of peers. Address count alone never establishes a role; the neighbour count does.

A railroad of this size is a geographically enormous enterprise: yards, terminals, dispatch centres, intermodal facilities and offices spread across 22 states, plus the signalling, dispatch and logistics systems that run them. An ample early /16 is exactly what an organisation with that many sites took in the days when addresses were handed out generously.

Notable

The single more-specific, one /24 announced alongside the covering /16, is the classic traffic-engineering gesture: pull one subnet's inbound traffic onto a preferred upstream, or protect one important range from being swallowed by a less-specific hijack, while leaving the rest of the /16 aggregated.

Reverse DNS returned nothing on the four addresses sampled. That is a sample, not a finding.