AS9971 SKB-DONGDAEMUNCABLEINTERNET-AS-KR SK Broadband Co Ltd

AS9971 (SKB-DONGDAEMUNCABLEINTERNET-AS-KR) is held by SK Broadband Co Ltd, and carries what was the Dongdaemun cable internet network — one of the regional cable operators that SK Broadband absorbed when it merged with the t-broad cable group. This is an access network for subscribers in its cable franchise area, not SK Broadband's national backbone: that is a different ASN.

What it's used for

RIS sees 6 announced IPv4 prefixes carrying 59,392 addresses, no IPv6, and only 1 observed BGP neighbour. That combination is decisive. Nearly sixty thousand addresses is far too much space for an enterprise or campus, but a single BGP neighbour rules out any transit, wholesale or hosting role — a network that sold connectivity or peered on its own account would show tens to hundreds of adjacencies. What is left is an eyeball network: a pool of subscriber addresses announced upward to exactly one upstream, which in this case is its own parent.

The prefix shape agrees. Three /18s (124.197.128.0/18, 27.115.128.0/18, 113.30.0.0/18) and a /19 supply almost all the space in clean, large aggregates — the way an access provider numbers a subscriber pool — with two small /22s from 103.51 and 45.112 making up the remainder.

Notable

• Read this ASN as a district-level cable ISP, not as SK Broadband nationally. Korean cable internet grew out of local franchise operators, and consolidation left their ASNs and address pools intact under the acquiring carrier's name.
• The single upstream is the parent network, which is why an ISP-sized address pool shows an enterprise-sized neighbour count.
• No IPv6 is announced, which is notable for a residential access network of this size.