Question : Ospf - single area vs multiple area

Can someone explain in practical terms what is the disadvantage of running OSPF in a single area vs. multi area. I would like to have as many details as possible - I am ccnp qualified so if you feel like being technical, even better.

Unfortunately, my ospf experience in large deployment scenarios is lacking which is why I am not able to answer this question myself; it's those situations when just reading the book, it's simply not enough.

Just to emphasize, i'd like a practical answer; from the network management point of view, to the more technical point of view; tips and tricks, recommendations, caveats, etc.

Much appreciated.

Answer : Ospf - single area vs multiple area

Summarization is one reason.

If you want to summarize routes in OSPF, you have to do it on an ABR. Which means multiple areas.

Another is if the area gets too big, the link state database can become large and unwieldy. Creating multiple areas effectively breaks up the database into smaller chunks.