OSPF Areas

Answered Question
Nov 23rd, 2008
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What would be the purpose of configurng an OSPF routing process on, say, a routed access layer switch, and giving it an OSPF process ID of 1, while creating an OSPF process on its OSPF neighbor and giving it a different process ID?


What is achieved by this? Two OSPF routers dont have to be using the same OSPF process ID to establish a neigborship and exchange routes, so what are the implications of using 2 different process IDs for adjacent OSPF routers?


Thanks


Victor

Correct Answer by Edison Ortiz about 8 years 6 months ago

No implications whatsover. The process ID is locally significant and allows you to have more than one OSPF process in a single OSPF capable device.


HTH,


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Edison.

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Correct Answer
Edison Ortiz Sun, 11/23/2008 - 18:14
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No implications whatsover. The process ID is locally significant and allows you to have more than one OSPF process in a single OSPF capable device.


HTH,


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Edison.

Richard Burts Sun, 11/23/2008 - 18:33
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Victor


While I agree with Edison that the OSPF process ID is locally significant, I will suggest a slightly different explanation of why there might be different OSPF process IDs. The underlying principle is that the OSPF process ID should be a predictable value. In many cases we achieve that by making the process ID the same in every router. But sometimes a different approach may be used: in my lab work preparing for the CCIE lab I would frequently make the router names R1, R2, R3, etc and make the OSPF process IDs 1, 2, 3, etc corresponding to the router host name. I have worked with a customer whose standard practice was to make the OSPF process id correspond to the OSPF router ID and with a customer whose standard practice was to make the OSPF process ID correspond to the OSPF area ID. It matters less what mechanism you use to assign process IDs and matters more that the assignment be logical and consistent.


HTH


Rick

lamav Tue, 11/25/2008 - 15:44
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Thanks, gentlemen, for your informative answers.


Appeciate it...


Victor

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