AS10164 SKB-GSD-AS-KR SK Broadband Co Ltd

SKB-GSD-AS-KR is a secondary autonomous system of SK Broadband, the

Seoul-headquartered fixed-line operator that is a wholly owned subsidiary of SK

Telecom and one of South Korea's largest broadband providers. Its main network is

[AS9318](https://asn.ipinfo.app/AS9318); this number carries a divisional slice

of the same estate.

What it's used for

• Holding and announcing a block of SK Broadband access space. The size and shape of the prefixes point at subscriber-facing use rather than servers.

Notable

The pack shows an unusual combination: 69,632 announced IPv4 addresses across

only 10 prefixes — a very high address-to-prefix ratio, built from /18 and

/19 aggregates such as 27.117.128.0/18, 110.35.96.0/19 and

180.150.192.0/19 — but just one observed BGP neighbour and no IPv6.

Read those together and the role is clear. Large contiguous aggregates announced

with a single adjacency is what an operator's internal AS looks like: it exists

as an addressing and policy container behind the parent network, and the outside

world only ever reaches it through SK Broadband proper. It is not a carrier (one

neighbour), not an enterprise (no enterprise holds 69k addresses in /18s), and

not a hosting network (hosting space is carved fine, not aggregated coarse).

Confidence is held low on the use rather than the operator. SK Broadband is

unambiguously an eyeball ISP and these are eyeball-shaped aggregates, but the

pack returned no reverse DNS on the addresses sampled, so nothing here

independently proves subscriber assignment over corporate access lines.

Interesting

• The mix includes recent APNIC blocks (45.112.88.0/22, 103.51.168.0/22) alongside older space, showing the AS still absorbs new allocations.