AS11172 Alestra, S. de R.L. de C.V.

AS11172 is Alestra, one of Mexico's major business telecommunications carriers. Alestra began as a joint venture built around AT&T's entry into the Mexican long-distance market and has since sat inside the Alfa/Axtel group; its market is corporate connectivity, managed networks, data centre and IT services, not consumer broadband.

What it's used for

Carrying a national enterprise network. RIS sees a genuinely large footprint: 924 announced IPv4 prefixes / 603,136 addresses, roughly 2,858 IPv6 prefixes, and 110 observed neighbours. The neighbour count is what places it — dozens of BGP adjacencies means it is selling connectivity and interconnecting with other carriers, while an enterprise of any size would peer with a handful.

Notable

Reverse DNS is uniform and first-party: sampled addresses across 189.206.0.0/16, 148.244.0.0/16, 201.163.0.0/16 and 201.151.0.0/16 all answer as static-<a>-<b>-<c>-<d>.alestra.net.mx. Two things follow. First, holder, address space and rDNS all agree, so this is a real operator's own inventory rather than announced third-party space. Second, the static- convention across the bulk of the space is consistent with fixed assignments to business sites, which matches Alestra's B2B positioning better than any dynamic consumer pool would.

Interesting

The very high IPv6 prefix count relative to IPv4 (thousands of /48s) is the fingerprint of per-customer IPv6 delegation: each corporate site gets its own /48, and many of them end up visible in the global table individually.