CentOS 7.x - yum update failed - Could not resolve host: mirrorlist.centos.org; Unknown error

 CentOS 7.x - yum update failed - Could not resolve host: mirrorlist.centos.org

[root@cent7-1 ]# yum update

Loaded plugins: fastestmirror, langpacks

Loading mirror speeds from cached hostfile

Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was

14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"

Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=extras&infra=stock error was

14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"

Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=updates&infra=stock error was

14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"

 * base: centos.uvigo.es

 * extras: centos.uvigo.es

 * updates: centos.uvigo.es

http://ftp.csuc.cat/centos/7.9.2009/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found

Trying other mirror.

To address this issue please refer to the below wiki article

https://wiki.centos.org/yum-errors

If above article doesn't help to resolve this issue please use https://bugs.centos.org/.

http://ftp.cixug.es/CentOS/7.9.2009/os/x86_64/repodata/repomd.xml: [Errno 14] HTTPS Error 404 - Not Found

Trying other mirror.

base                                                                                  | 3.6 kB  00:00:00

http://repo.nixval.com/CentOS/7.9.2009/extras/x86_64/repodata/repomd.xml: [Errno 14] curl#6 - "Could not resolve host: repo.nixval.com; Unknown error"

Trying other mirror.

http://mirror.uv.es/mirror/CentOS/7.9.2009/extras/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found

Trying other mirror.

^X^Z

[1]+  Stopped                 yum update

[root@cent7-1 ]# ^C

[root@cent7-1 ]# ping google.com

PING google.com (142.250.183.14) 56(84) bytes of data.

64 bytes from bom07s30-in-f14.1e100.net (142.250.183.14): icmp_seq=1 ttl=59 time=32.1 ms

CentOS 7 has reached its End of Life (EOL) and the official mirrors have been removed. To resolve this, you'll need to update your repository URLs to point to the CentOS vault

Backup/move  the existing repos under /etc/yum.repos.d/* 

vi /etc/yum.repos.d/CentOS-Base.repo

[base]

name=CentOS-$releasever - Base

baseurl=https://vault.centos.org/7.9.2009/os/$basearch

gpgcheck=1

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

[updates]

name=CentOS-$releasever - Updates

baseurl=https://vault.centos.org/7.9.2009/updates/$basearch

gpgcheck=1

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

[extras]

name=CentOS-$releasever - Extras

baseurl=https://vault.centos.org/7.9.2009/extras/$basearch

gpgcheck=1

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

Clean the yum cache and update:

sudo yum clean all

sudo yum makecache

sudo yum update

[root@cent7-1 yum.repos.d]# sudo yum clean all

Loaded plugins: fastestmirror, langpacks

Cleaning repos: base extras updates

[root@cent7-1 yum.repos.d]# sudo yum makecache

Loaded plugins: fastestmirror, langpacks

Determining fastest mirrors

base                                                                                  | 3.6 kB  00:00:00

extras                                                                                | 2.9 kB  00:00:00

updates                                                                               | 2.9 kB  00:00:00

(1/10): base/x86_64/group_gz                                                          | 153 kB  00:00:00

(2/10): base/x86_64/primary_db                                                        | 6.1 MB  00:00:02

(3/10): base/x86_64/filelists_db                                                      | 7.2 MB  00:00:03

(4/10): base/x86_64/other_db                                                          | 2.6 MB  00:00:00

(5/10): extras/x86_64/filelists_db                                                    | 305 kB  00:00:00

(6/10): extras/x86_64/other_db                                                        | 154 kB  00:00:00

(7/10): extras/x86_64/primary_db                                                      | 253 kB  00:00:00

(8/10): updates/x86_64/primary_db                                                     |  27 MB  00:00:06

(9/10): updates/x86_64/other_db                                                       | 1.6 MB  00:00:00

(10/10): updates/x86_64/filelists_db                                                  |  15 MB  00:00:07

Metadata Cache Created

[root@cent7-1 yum.repos.d]# sudo yum update

Loaded plugins: fastestmirror, langpacks

Loading mirror speeds from cached hostfile

Resolving Dependencies

--> Running transaction check

---> Package NetworkManager.x86_64 1:1.18.8-1.el7 will be updated

---> Package NetworkManager.x86_64 1:1.18.8-2.el7_9 will be an update

---> Package NetworkManager-adsl.x86_64 1:1.18.8-1.el7 will be updated

---> Package NetworkManager-adsl.x86_64 1:1.18.8-2.el7_9 will be an update

---> Package NetworkManager-glib.x86_64 1:1.18.8-1.el7 will be updated

---> Package NetworkManager-glib.x86_64 1:1.18.8-2.el7_9 will be an update

---> Package NetworkManager-libnm.x86_64 1:1.18.8-1.el7 will be updated

---> Package NetworkManager-libnm.x86_64 1:1.18.8-2.el7_9 will be an update

---> Package NetworkManager-ppp.x86_64 1:1.18.8-1.el7 will be updated

---> Package NetworkManager-ppp.x86_64 1:1.18.8-2.el7_9 will be an update

---> Package NetworkManager-team.x86_64 1:1.18.8-1.el7 will be updated

---> Package NetworkManager-team.x86_64 1:1.18.8-2.el7_9 will be an update