Summary
- Hostname
- —
- ASN
- AS4538
- Organization
- China Education and Research Network
- Network
- CERNET-CN
- Range
- 202.112.0.0 - 202.121.255.255
- /24 block
- 202.121.128.0/24
- Country
- CN
- Blacklists
- 0 of 14
- Abuse contact
- [email protected]
Presence of 202.121.128.143 in blacklists
| List | Status |
|---|---|
| zen.spamhaus.org | Not listed |
| bl.spamcop.net | Not listed |
| black.junkemailfilter.com | Not listed |
| multi.surbl.org | Not listed |
| dnsbl.sorbs.net | Not listed |
| b.barracudacentral.org | Not listed |
| dnsbl.tornevall.org | Not listed |
| dnsbl.httpbl.org | Not listed |
| dnsbl-1.uceprotect.net | Not listed |
| dnsbl-2.uceprotect.net | Not listed |
| dnsbl-3.uceprotect.net | Not listed |
| v4.fullbogons.cymru.com | Not listed |
| bl.blocklist.de | Not listed |
| rbl.blockedservers.com | Not listed |
What is a blacklist (RBL)?
An RBL (Real-time Blackhole List), also known as a DNSBL (DNS-based Blackhole List), is a mechanism used to fight spam by blocking e-mails coming from sources known to send spam. RBLs are databases listing the IP addresses deemed responsible for sending unsolicited e-mail. Mail server administrators use these lists to filter incoming e-mails by checking whether the sender's IP address appears in one or more RBLs. If it does, the e-mail may be rejected or subjected to additional checks.
There are different types of RBLs, each with its own criteria for listing IP addresses. Some focus on IP addresses that send spam directly, while others list IP addresses belonging to networks known to host computers infected with malware and used as bots to send spam. RBL operators keep their lists up to date through automatic and manual contributions, and IP address owners can often request removal from a list if they believe the listing is unjustified.
WHOIS data for 202.121.128.143
% [whois.apnic.net]
% Whois data copyright terms http://www.apnic.net/db/dbcopyright.html
% Information related to '202.112.0.0 - 202.121.255.255'
% Abuse contact for '202.112.0.0 - 202.121.255.255' is '[email protected]'
inetnum: 202.112.0.0 - 202.121.255.255
netname: CERNET-CN
descr: China Education and Research Network
descr: China Education and Research Network Center
descr: Tsinghua University
descr: Beijing, 100084
country: CN
admin-c: CER-AP
tech-c: CER-AP
abuse-c: AC1685-AP
status: ALLOCATED PORTABLE
remarks: origin AS4538
mnt-by: APNIC-HM
mnt-lower: MAINT-CERNET-AP
mnt-routes: MAINT-CERNET-AP
mnt-irt: IRT-CERNET-AP
last-modified: 2020-09-03T09:16:29Z
source: APNIC
irt: IRT-CERNET-AP
address: Network Center,
address: FIT-3-220, Tsinghua Univ
address: Beijing 100084, China
phone: +86-10-62784301
fax-no: +86-10-62785933
e-mail: [email protected]
abuse-mailbox: [email protected]
admin-c: CER-AP
tech-c: CER-AP
auth: # Filtered
remarks: timezone GMT+8
remarks: [email protected] was validated on 2026-09-10
mnt-by: MAINT-CERNET-AP
last-modified: 2026-09-10T07:51:56Z
source: APNIC
role: ABUSE CERNETAP
country: ZZ
address: Network Center,
address: FIT-3-220, Tsinghua Univ
address: Beijing 100084, China
phone: +86-10-62784301
e-mail: [email protected]
admin-c: CER-AP
tech-c: CER-AP
nic-hdl: AC1685-AP
remarks: Generated from irt object IRT-CERNET-AP
remarks: [email protected] was validated on 2026-09-10
abuse-mailbox: [email protected]
mnt-by: APNIC-ABUSE
last-modified: 2026-09-10T07:52:32Z
source: APNIC
role: CERNET Helpdesk
address: CERNET Center
address: Beijing 100084, China
country: CN
phone: +86-10-6278-4049
fax-no: +86-10-6278-5933
e-mail: [email protected]
remarks: [email protected]
admin-c: XL1-CN
tech-c: SZ2-AP
nic-hdl: CER-AP
mnt-by: MAINT-CERNET-AP
last-modified: 2020-09-03T09:14:12Z
source: APNIC
% Information related to '202.120.0.0/15AS4538'
route: 202.120.0.0/15
descr: CERNET
origin: AS4538
mnt-by: MAINT-CERNET-AP
last-modified: 2026-06-17T08:11:41Z
source: APNIC
% This query was served by the APNIC Whois Service version 1.88.48 (WHOIS-UK2)
Related domain names
Domains mentioned in the reverse DNS and the WHOIS of 202.121.128.143.
What is an IP address?
An IP address is a unique identifier on the internet that identifies a server or an internet user. Here the IP address is 202.121.128.143: it may be the unique address used to reach a website, or the unique address of an internet user.
An SMTP server (a server used to send e-mails) must have a reverse DNS record associated with its IP address