Autonomous System
AS4538 China Education and Research Network Center
EducationActiveChinaAPNIC
AS4538 (ERX-CERNET-BKB) is an education network operated by China Education and Research Network Center in China, registered with APNIC. It has 5,043 IPv4 prefixes with 42,262,016 addresses and 4,880 IPv6 prefixes, which makes it the 15th largest of 82,200 active autonomous systems by IPv4 space.
IPv4 addresses42,262,016in 5,043 prefixes
IPv6 prefixes4,880≈ 3.2 × 10³² addresses
Size rank#15of 82,200 active ASNs
Details
OrganizationChina Education and Research Network Center
AS nameERX-CERNET-BKB
Websitecernet.edu.cn
Country China (CN)
Network typeEducation
RegistryAPNIC
Abuse contactabuse@cernet.edu.cn
Registered—
Last updated2025-10-31
IPv4 prefixes
5,043 prefixes · 42,262,016 addresses| Network | Addresses | First – last address |
|---|---|---|
| 58.192.0.0/12 | 1,048,576 | 58.192.0.0 – 58.207.255.255 |
| 59.64.0.0/12 | 1,048,576 | 59.64.0.0 – 59.79.255.255 |
| 202.192.0.0/12 | 1,048,576 | 202.192.0.0 – 202.207.255.255 |
| 210.32.0.0/12 | 1,048,576 | 210.32.0.0 – 210.47.255.255 |
| 222.16.0.0/12 | 1,048,576 | 222.16.0.0 – 222.31.255.255 |
| 222.192.0.0/12 | 1,048,576 | 222.192.0.0 – 222.207.255.255 |
| 58.200.0.0/13 | 524,288 | 58.200.0.0 – 58.207.255.255 |
| 125.216.0.0/13 | 524,288 | 125.216.0.0 – 125.223.255.255 |
| 202.112.0.0/13 | 524,288 | 202.112.0.0 – 202.119.255.255 |
| 202.200.0.0/13 | 524,288 | 202.200.0.0 – 202.207.255.255 |
| 211.64.0.0/13 | 524,288 | 211.64.0.0 – 211.71.255.255 |
| 211.80.0.0/13 | 524,288 | 211.80.0.0 – 211.87.255.255 |
| 218.192.0.0/13 | 524,288 | 218.192.0.0 – 218.199.255.255 |
| 219.216.0.0/13 | 524,288 | 219.216.0.0 – 219.223.255.255 |
| 219.224.0.0/13 | 524,288 | 219.224.0.0 – 219.231.255.255 |
| 222.16.0.0/13 | 524,288 | 222.16.0.0 – 222.23.255.255 |
| 222.24.0.0/13 | 524,288 | 222.24.0.0 – 222.31.255.255 |
| 49.52.0.0/14 | 262,144 | 49.52.0.0 – 49.55.255.255 |
| 49.120.0.0/14 | 262,144 | 49.120.0.0 – 49.123.255.255 |
| 59.64.0.0/14 | 262,144 | 59.64.0.0 – 59.67.255.255 |
| 101.4.0.0/14 | 262,144 | 101.4.0.0 – 101.7.255.255 |
| 115.24.0.0/14 | 262,144 | 115.24.0.0 – 115.27.255.255 |
| 121.192.0.0/14 | 262,144 | 121.192.0.0 – 121.195.255.255 |
| 121.248.0.0/14 | 262,144 | 121.248.0.0 – 121.251.255.255 |
| 122.204.0.0/14 | 262,144 | 122.204.0.0 – 122.207.255.255 |
58.192.0.0/12 59.64.0.0/12 202.192.0.0/12 210.32.0.0/12 222.16.0.0/12 222.192.0.0/12 58.200.0.0/13 125.216.0.0/13 202.112.0.0/13 202.200.0.0/13 211.64.0.0/13 211.80.0.0/13 218.192.0.0/13 219.216.0.0/13 219.224.0.0/13 222.16.0.0/13 222.24.0.0/13 49.52.0.0/14 49.120.0.0/14 59.64.0.0/14 101.4.0.0/14 115.24.0.0/14 121.192.0.0/14 121.248.0.0/14 122.204.0.0/14
The 25 largest of 5,043. The API and the database have all of them.
IPv6 prefixes
4,880 prefixes- 2001:252::/32
- 2401:cc00::/32
- 2402:2000::/32
- 2402:e740::/32
- 2402:f000::/32
- 2403:3140::/32
- 2403:8c00::/32
- 2403:ac00::/32
- 2403:d400::/32
- 2405:d900::/32
- 2406:280::/32
- 2406:3340::/32
- 240a:a000::/32
- 240a:a001::/32
- 240a:a002::/32
- 240a:a003::/32
- 240a:a004::/32
- 240a:a005::/32
- 240a:a006::/32
- 240a:a007::/32
- 240a:a008::/32
- 240a:a009::/32
- 240a:a00a::/32
- 240a:a00b::/32
- 240a:a00c::/32
2001:252::/32 2401:cc00::/32 2402:2000::/32 2402:e740::/32 2402:f000::/32 2403:3140::/32 2403:8c00::/32 2403:ac00::/32 2403:d400::/32 2405:d900::/32 2406:280::/32 2406:3340::/32 240a:a000::/32 240a:a001::/32 240a:a002::/32 240a:a003::/32 240a:a004::/32 240a:a005::/32 240a:a006::/32 240a:a007::/32 240a:a008::/32 240a:a009::/32 240a:a00a::/32 240a:a00b::/32 240a:a00c::/32
The 25 largest of 4,880. The API and the database have all of them.
Query AS4538 with the API
The ASN lookup returns everything on this page as JSON, including every prefix. ASN lookups need an API key: a free account comes with 1,000 requests a day.
curl "https://api.ipapi.is/?q=AS4538&key=YOUR_API_KEY"
Any address in its prefixes resolves to AS4538, with or without a key:
curl "https://api.ipapi.is/?q=58.192.0.1"
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