Greg Ferro of Ethereal Mind writes:
Overlay networking has been around for a year or so now and the ideas behind it are well established. It was about 3/4 weeks ago while researching VTEP functionality in Dell and Arista switches that I realised I could build manually configured tunnels with VXLAN and get the same results as an EoMPLS x-connect with almost zero effort. More importantly, I don’t have to pay for expensive hardware that has MPLS functions or pay again for software licenses to upgrade with MPLS features.
Greg has stated time and again that MPLS in the data center is a non-starter. Here’s a post with diagrams to show exactly why that is.