AS9978 UOS-AS The University of Seoul

AS9978 (UOS-AS) is held by the University of Seoul (서울시립대학교), the public university run by the Seoul Metropolitan Government. The reverse DNS confirms it directly: 203.249.96.5 resolves to ns1.uos.ac.kr, the university's own nameserver in its own uos.ac.kr domain, sitting inside its largest announced block.

What it's used for

This is a campus network. RIS sees 4 announced IPv4 prefixes totalling 6,656 addresses, no IPv6, and 3 observed BGP neighbours. The mix of block sizes is typical of a Korean university: a 203.249.96.0/20 as the historical core allocation, a 210.125.176.0/21 alongside it, and two single /24s (1.229.202.0/24 and 222.109.143.0/24) picked up later from different pools. Around 6,700 addresses is a sensible campus footprint — enough for departmental subnets, labs, lecture-hall wireless and the public-facing web, mail and DNS services, without the scale that would suggest hosting for outsiders.

Three neighbours is the signature of an institution that buys connectivity rather than selling it: in Korea that usually means a commercial upstream plus a connection to the national research and education network, which gives the campus a research path and a commodity path.

Notable

• The University of Seoul is municipally funded rather than national, and is known for its low tuition policy, which is unusual among Korean universities.
• No IPv6 is announced from this AS, which is common among Korean campuses of this vintage but does leave the network v4-only at the routing layer.