Once an interviewer asked me, "Can we use OSPF without area 0?" I was not able to answer at that time.

Later on, I searched, but I did not not find a satisfactory answer for this question. So, can we really use OSPF without Area 0?

  • Possible duplicate of Why must all areas connect to an Area 0 backbone in OSPF?
    – JFL
    Mar 2, 2017 at 10:57
  • It not duplicate, I read related questions. my question is pity simple can we use OSPF without area 0? Mar 2, 2017 at 11:29
  • Isn't it obvious from the linked question? If you have multiple area the answer is no. If you have a single area, I suppose it can be something else than area 0 but there's no point.
    – JFL
    Mar 2, 2017 at 11:59
  • Did you get the job ?
    – psniffer
    Mar 2, 2017 at 19:46
  • I have a same question as well. I said "It's a backbone area and mandatory in OSPF protocol"...I didn't get the job thou :)
    – user34885
    Mar 2, 2017 at 20:27

4 Answers 4


There is only one way to use OSPF without an Area 0, and that is to use OSPF with a single area. If you only have one OSPF area, you can number it any way you like, but if you have even two areas, you must have an Area 0.


OSPF can work efficiently without area 0 when there is only one area. When there is a need for more areas, OSPF traffic should pass through the backbone area (area 0) to avoid the routing loop.

OSPF runs Link State protocol inside the area, However, it uses Distance Vector protocol to advertise the routes between areas. The Distance Vector protocol is vulnerable to the routing loops, therefore, the traffic from one area to another must pass through area 0.


If not using area 0 or backbone area then it means that single area ospf is being implemented here..

What is single area ospf read it here:- http://learnwow.blogspot.in/2017/10/ospf-in-networking-top-standout-characteristics.html


No OSPF should have a backbone area because it acts as a hub to transmit routing information about other areas in the network.

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