Open Virtual Network (OVN) is a subproject of Open vSwitch (OVS), a performant, programmable, multi-platform virtual switch. OVN adds to the OVS existing capabilities the support for overlay networks by introducing virtual network abstractions such as virtual switches and routers. Moreover, OVN provides native methods for setting up Access Control Lists (ACLs) and network services such as DHCP.Many Red Hat products, such as Red Hat OpenStack Platform and Red Hat Virtualization, are now using OVN, andRed Hat OpenShift Container Platform will be using OVN soon.
In this article, I’ll cover howOVNARP/ND_NS actions work, the mainlimitations in the current implementation, and howto overcome those. First, I’ll provide a brief overview of OVN’s architecture to facilitate the discussion: