How to reinstall kernel on CentOS?

Question

linux

Centos 6.5, yum updated the kernel to version 2.6.32-504.el6, as a result of which the network stopped working. I want to roll back the kernel.
rpm-qa | grep kernel shows kernel 2.6.32-431.3.1.el6
According to mattiasgeniar.be/2012/07/23/reinstall-the-linux-ke... I can remove the current kernel with yum remove command. However, the system skips it (Skipping the running kernel). How to be?

Answer 1

I don’t know about CentOS, but usually the kernel is placed next to the previous one. If you didn't remove it - when booting into grub or whatever, you should have an additional menu item that has all installed kernels. Just select it, then delete the new one so that the old one is loaded by default.

Answer 2

Depends on the version of GRUB change which kernel to load by default
/boot/grub/menu.lst - the default= line
or
/boot/grub/grub.cfg - the line set default=
0 - the first in the list
1 - the second
...
delete after loading unnecessary core