AS8400 TELEKOM-AS

TELEKOM-AS is Telekom Srbija a.d., Serbia's state-controlled incumbent

telecom operator, which sells fixed and mobile service under the mts brand. This

is its main network AS.

What it's used for

• Consumer broadband across Serbia. Reverse DNS is explicit: IP-ADDR.dynamic.isp.telekom.rs on the large blocks, which is a straightforward dynamic subscriber pool naming scheme.
• Space inherited from acquired cable operators, still resolving under their own domains. Prefixes in the AS carry cpe.vektor.net and cpe.sn.co.rs dynamic CPE names, the fossils of regional ISPs Telekom Srbija bought up during Serbia's cable consolidation.
• Around 820,000 IPv4 addresses across roughly 90 prefixes, with a legacy 212.200.0.0/16 at the core of it.

Notable

• An eyeball network, and one of the largest in the region. The addresses front Serbian households, so they geolocate to end users rather than to servers or datacentres.
• The mix of reverse-DNS domains inside one AS is the tell that this network grew by acquisition rather than only organically. Whole customer bases were moved under the incumbent's routing while keeping their old naming.

Interesting

• Telekom Srbija's buying spree in the Serbian cable and ISP market was politically contentious at home, and the routing table quietly records it: the acquired operators' names survive in reverse DNS long after their brands stopped appearing on bills.