OSPF Network Type in VXLAN the Underlay

OSPF, by default, uses the broadcast network type on Ethernet interfaces, which involves a DR/BDR election. However, when OSPF is deployed as the underlay routing protocol for a VXLAN topology, the network type can be configured as point to point. This is because, in a spine and leaf architecture which is used by VXLAN, the DR/BDR election is unnecessary, because only point to point links exist between spine and leaf switches.

Although a broadcast network type would work, by employing a point to point network type, the Link State Database (LSDB) is kept smaller, streamlining network efficiency. While this optimization might not impact smaller network labs significantly, it becomes crucial in larger, complex spine and leaf deployments to enhance performance and scalability.

https://networklessons.com/vxlan/vxlan-flood-and-learn-multicast-data-plane