Max areas per OSPF process

Ever wondered how many OSPF areas are supported in single OSPF process?

I am not sure about Cisco, although it seems this is neither documented in H3C or in Cisco documents. I had to learn it through the hard way, and it seems the H3C routers supports only 50 areas per OSPF process (confirmed on MSR 30-40). Once you have 50 areas in a process, and you try to create 51st area, you shall encounter the error:

"warning: ospf 1 maximum limit reached"

The OSPF that I encountered this error was having following details:

<ROUTER>display ospf br

         OSPF Process 1 with Router ID
                 OSPF Protocol Information

 RouterID:     Router Type:  ABR  ASBR  NSSA
 Route Tag: 0
 Multi-VPN-Instance is not enabled
 Applications Supported: MPLS Traffic-Engineering
 SPF-schedule-interval: 5
 LSA generation interval: 5
 LSA arrival interval: 1000
 Transmit pacing: Interval: 20 Count: 3
 Default ASE parameters: Metric: 1 Tag: 1 Type: 2
 Route Preference: 10
 ASE Route Preference: 150
 SPF Computation Count: 899
 RFC 1583 Compatible
 Graceful restart interval: 120
 Area Count: 50  Nssa Area Count: 49
 ExChange/Loading Neighbors: 0

If you have more than 50 areas, you will need to add another process in the OSPF and then add the new areas in that new process, and then redistribute both processes in to each other...


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