Errorres multilib en Centos

Si al actualizar Centos nos da errores multilib estilo:

Error:  Multilib version problems found. This often means that the root
       cause is something else and multilib version checking is just
       pointing out that there is a problem. Eg.:
      
....

       Versiónes multilib protegidas: nss-softokn-freebl-3.28.3-8.el7_4.i686 != nss-softokn-freebl-3.16.2.3-14.4.el7.x86_64
Error: Versiónes multilib protegidas: pcre-8.32-17.el7.i686 != pcre-8.32-15.el7_2.1.x86_64
Error: Versiónes multilib protegidas: libselinux-2.5-11.el7.i686 != libselinux-2.5-6.el7.x86_64


El problema puede estar en un lio con los repositorios.
Podemos eliminar los repositorios que no usemos, eliminado sus paquetes:
yum remove epel-release-7-9.noarch
yum remove centos-release-7-3.1611.el7.centos.x86_64

Si aun así no funciona, puede que esto ayude:

Updating a system without checking the packages being installed as deps pulls in various i686 packages. This is due to rdma. More on this behaviour can be found here. As a workaround you can use this command yum update rdma-core.x86_64 && yum update. If you see transaction check conflicts when trying to install rdma-core, try yum update rdma-core.x86_64 ibacm instead. 

Info obtenida de:

https://www.centos.org/forums/viewtopic.php?t=64509
https://wiki.centos.org/Manuals/ReleaseNotes/CentOS7