AS10370 NORTHWEST-AIRLINES

NORTHWEST-AIRLINES is registered to Northwest Airlines, a carrier that merged

into Delta Air Lines in 2008 and whose brand was retired in 2010. The AS and

its address space have outlived the airline: the registration still carries

Delta-side administrative contacts, and the network is in practice Delta's.

What it's used for

• Corporate airline networking: the systems an airline runs behind the scenes — reservations and departure-control back ends, station and airport office connectivity, staff and administrative infrastructure.
• The footprint is two legacy class-B allocations, 147.118.0.0/16 and 139.72.0.0/16, plus three /24 more-specifics out of the latter. Pre-CIDR class-Bs are what a large 1990s corporate IT department was handed, and airlines were among the earliest heavy enterprise computing users.

Notable

• Enterprise, not carrier. RIS sees 5 IPv4 prefixes / 131,072 addresses announced with just 2 observed BGP neighbours. Two upstreams behind 131k addresses is the definitive end-site signature: a network with this much space that sold connectivity would peer with hundreds of ASes. It buys transit for itself.
• The handle is a good example of why an AS name is evidence in neither direction. Handles outlive their holders, and this one names an airline that has not existed for over fifteen years.

Interesting

• Delta runs its own ASNs as well — [AS14925](https://asn.ipinfo.app/AS14925) (Delta Air Lines) and [AS26034](https://asn.ipinfo.app/AS26034) (Delta Technology). That AS10370 survives alongside them, still announcing the old Northwest class-Bs, is the routing table quietly recording a corporate merger that was never fully renumbered.