Google interview question

How does the BDR get elected in OSPF?

Interview Answers

Anonymous

9 Sept 2014

The DR is selected with the router having the highest priority, but because all the routers have a priority of 1 out of the box, the hight Router ID wins, so the second highest router ID become the BDR.

2

Anonymous

29 Mar 2020

Highest Router-ID becomes DR and the 2nd highest Router-ID becomes BDR in OSPF. It is a priority which elect DR primarily (by default 1 on all). If that matches on all due to its default nature, it will go to Highest IP address of the router loopback interface first and later to the other interface if needed.