OSPF - DR-BDR election priority of zero
When implementing OSPF, on any network segment where more than two OSPF routers may be present (such as a multiaccess segment which uses Ethernet for example), an OSPF DR/BDR election takes place. One of the criteria that is examined for this election is the configured priority value of the OSPF router.
By setting the priority to zero, you are essentially saying that you don’t want this router to participate in an election. In other words, it states that this router is ineligible to become the DR or the BDR. It will necessarily become a DROTHER.
Now if all routers within a network segment are set with a priority of 0, no router will be eligible to become a DR or BDR, and thus the election will fail.