Autonomous system
AS9757 CMBI-AS-KR CMB DONDAEMOON BROADCASTING
Residential APNIC
Summary
CMB Dongdaemun Broadcasting
isp residential legacy
AS9757 (CMBI-AS-KR) is registered to CMB Dongdaemun Broadcasting, one of the regional cable system operators inside CMB, a South Korean cable MSO. CMB traces back to a wired music-broadcasting business and today runs cable television and cable broadband across parts of Seoul, Daejeon, South Chungcheong, Gwangju and Daegu. This AS is the Seoul (Dongdaemun-area) piece of that group.
What it's used for
The address space is cable-subscriber space: 60 IPv4 prefixes covering 32,768 addresses, no IPv6, and 2 observed BGP neighbours. The inventory is two /18 aggregates — 110.34.64.0/18 and 122.128.192.0/18, which account for the whole 32,768 addresses — sliced into a dense run of /21s, /22s and /24s. Contiguous space chopped into small equal-sized blocks is what a cable operator's access aggregation looks like: each block maps to a headend or service area rather than to a distinct customer organisation.
The two-neighbour count confirms the eyeball reading. A network holding 32,768 addresses could in principle be a small regional carrier, but a carrier peers; this one has two adjacencies, so it buys transit and originates only its own subscriber pools. No customer cone, no sign of transit or hosting.
Notable
- CMB is one of the last independent Korean cable MSOs. Most of its peers were absorbed by mobile carriers — HCN by KT, CJ HelloVision by LG Uplus, t-broad by SK Broadband.
- This is a single regional SO within CMB, not the group's whole national footprint.
- The two /18s are announced both whole and in pieces, so the prefix count overstates how much distinct space is involved.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Interconnection
Peering at a glance
Internet exchanges
No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-22, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 28 prefixes · 32.77K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| KR | Korea, Republic of | 28 |
Registry
Allocation record
- Registry
- APNIC
- Handle
AS9757- Registry name
- CMBI-AS-KR-KR
- Abuse contact
- hostmaster@nic.or.kr
- Registered
- 1999-12-10
- Allocation
- allocated
Routing security
RPKI and IRR
- RPKI
- 0% valid · 0 valid, 60 with no ROA
- ROAs
- 0 authorising AS9757
- ASPA
- no ASPA record
- IRR
- 100% registered · 60 of 60 announcements
- Route objects
- 71 naming AS9757
Reputation
Classification and threat
Residential Fixed-line consumer ISP. Addresses here are homes.
Spamhaus DROP
Not on ASN-DROP The network as a whole is not listed.
No DROP prefixes None of its announced space is on the DROP prefix list.
Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 442 networks and 1,779 prefixes, as published 2026-10-23. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.
FBI IC3
No IC3 indicators Nothing from the FBI IC3 feed.
IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere