AS10880 YAHOO-AN2

YAHOO-AN2 is one of Yahoo's autonomous systems, registered to Yahoo Holdings Inc. It is a small satellite AS rather than Yahoo's main backbone, and the routing shows it doing a specific job.

What it's used for

Serving Yahoo's own content and services from scattered edge locations. RIS shows 6 announced IPv4 prefixes totalling only 1,536 addresses, 6 announced IPv6 prefixes, and 1 observed neighbour.

The address count is tiny, but the geography of those addresses is the point. The v4 prefixes are six separate /24s pulled from wildly different registries: 68.180 and 209.191 are ARIN space, 202.165 and 203.84 are APNIC space. The six IPv6 /48s repeat the pattern, with blocks from 2406:: (Asia-Pacific), 2001:4998:: (Yahoo's own long-held allocation) and 2804:: (Latin America). A network that announces one /24 and one /48 per region, and nothing bigger anywhere, is a set of points of presence, not a datacentre footprint.

Every sampled address, in every region, answers to unknown.yahoo.com. That is Yahoo's generic default reverse record, and its uniformity across ARIN and APNIC space is strong confirmation that all six prefixes are first-party Yahoo infrastructure rather than customer or leased space wearing someone else's rDNS.

Notable

Yahoo runs several ASNs; this one behaves like a content edge, and the lone observed neighbour is consistent with it hanging off Yahoo's own backbone rather than buying transit independently.

Interesting

Yahoo's address space is a fossil record of the 1990s commercial internet: blocks from four continents, held continuously through the Yahoo, Altaba, Oath, Verizon Media and Apollo eras, still routed under a low-numbered ASN.