OSPF point to point network type for Ethernet

A point to point OSPF network type is one that is used between two directly connected routers. This network type eliminates the need for a DR/BDR election.

This network type was originally devised to enable OSPF across technologies that are by definition point to point, such as serial links, Point-to-Point Protocol (PPP), High Level Data Link Control (HDLC), and others. However, it can also be used for multi-access technologies such as Ethernet.

If you have two directly connected routers over an Ethernet link and you know you won’t be adding another router to that particular network segment, then yes, it would be correct to set up the link as a point-to-point network for OSPF. The result would be that there would be no DR/BDR elections on that particular network segment.

Technically speaking, this can be achieved. The question, however, is, why would you do it? The DR/BDR election is not particularly resource-intensive, regardless of how many routes are advertised on your OSPF network. Nor is it particularly time-consuming to affect convergence time in any substantial way. Unless you have a central OSPF router with dozens or even hundreds of point-to-point Ethernet links to other OSPF routers, making such links point-to-point for OSPF will have little to no substantial benefit. By no means is it incorrect, in fact, it is theoretically more efficient.

The question however remains, is the change worth the marginal benefit? It really depends on how each administrator approaches it, and what they consider best practice. Also keep in mind that if in the future you (or your successor) happen to add another router to that particular network segment (by adding a switch for example), you will have to remember to remove that particular command from both of the OSPF routers, which is an additional point of failure in the process.

Links

https://networklessons.com/ospf/ospf-point-to-point-network-type-over-frame-relay/