How to revert Centos 6.5 repositories to default?

Question

linux

On the server, someone before me deleted the repositories.
I copied the /etc/yum.repos.d folder from a known good machine.
tried to install gcc-c++ and got 404 error from some left repository.
On a working machine, everything is fine.
How would I restore the repositories on the first machine?

Answer 1

execute sequentially under root:

yum clean all
yum makecache

this will clear the current caches and rebuild them using /etc/yum.repos.d