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Maximum OSPF processes on a router?

What is the maximum number of OSPF processes that a router can run? In a book I read the following:

"when provisioning for PE-to-CE connectivity, it is important to bear in mind that the current IOS implementation provides a maximum of 32 protocol descriptor blocks (PDBs) per PE router.

One PDB is used per protocol instance, including static and connected.

If OSPF is used for PE-CE connectivity, separate OSPF processes are required (1 per VRF), and 1 PDB is used per VRF where you run an OSPF process."

So does that mean that only 32 OSPF processes can be run on a single router? If someone can confirm this, I would appreciate it!



Re: Maximum OSPF processes on a router?

Yes, that is correct. After one PDB is used for static, (if you have any) and one for all the connected interfaces, you have 30 left. OSPF is an overhead to the CPU due to its LS calculations, and having multiple instance of OSPF, in case of an MPLS VPN, increases the load on the CPU. Hence the limitation.


Re: Maximum OSPF processes on a router?

The router is limited to 30 dynamic routing processes overall, not just OSPF processes. I believe there is some work going into lifting this limitation, email me off line and I can look it up.


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