Question 750
Four OSPF routers become eligible simultaneously on an Ethernet broadcast segment, with no existing DR/BDR: R1 (priority 1, router ID 10.255.0.26); R2 (priority 1, router ID 10.255.0.14); R3 (priority 1, router ID 10.255.0.166); R4 (priority 1, router ID 10.255.0.170). All four routers now have equal interface priority. Which router wins the DR election based on the router-ID tie-breaker?
Explanation
Correct Answer
All routers have equal OSPF priority 1; the highest router ID, 10.255.0.170, wins the DR election.
Incorrect Answers
R3 has the same priority as its peers but router ID 10.255.0.166 is below 10.255.0.170; router ID decides a priority tie.
R1 has the same priority as its peers but router ID 10.255.0.26 is below 10.255.0.170; router ID decides a priority tie.
R2 has the same priority as its peers but router ID 10.255.0.14 is below 10.255.0.170; router ID decides a priority tie.