How to resolve baseurl issue with CentOS-Base.repo on Linux (Centos 6.7) to run "yum install ftp"

I am working in installing FTP and found this issue that I am unable to install yum. Referred many places and did yum clean all and configured CentOs-Base.repo to have vault as baseurl for -Base. I am still unable to install ftp using yum. I get the below error:

[root@ts-htn-01 yum.repos.d]# yum update
Loaded plugins: fastestmirror, security
Setting up Update Process
Repository base is listed more than once in the configuration
Repository updates is listed more than once in the configuration
Repository extras is listed more than once in the configuration
Repository centosplus is listed more than once in the configuration
Repository contrib is listed more than once in the configuration
Repository '-dc' is missing name in configuration, using id
Loading mirror speeds from cached hostfile
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os&infra=stock error was
14: PYCURL ERROR 7 - "couldn't connect to host"
https://vault.centos.org/6.7/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"
Trying other mirror.
Error: Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again
[root@ts-htn-01 yum.repos.d]#

My http service is running:

[root@ts-htn-01 yum.repos.d]# service httpd status
httpd (pid  6650) is running...
[root@ts-htn-01 yum.repos.d]#

My ping to vault and mirrorlist links are working fine. Should I add this to host connections..? If yes, please let me know how. Please help. Thanks in advance.

Hello,

The first thing to check here is whether or not you can actually resolve and connect to both mirrorlist.centos.org and vault.centos.org from your system. The fact that your own local Web server is running has no bearing on the situation, since when using yum you're trying to connect to the CentOS repository Web servers, and not your own local Web server.

So, firstly, can you resolve both of these names, either via nslookup or host ? And secondly, from your server can you connect to TCP ports 80 and 443 on both these hosts ? If the answer to either or both of these is 'no', then you need to correct the underlying network issue first, and then once you are able to both resolve and connect to the CentOS vault servers, at that point re-try your yum commands and see if anything is different.

If you can already resolve and connect to both these addresses, then please let us know and we can then take things from there. Hope this helps !