OSPF: UNDERSTANDING PROCESS ID TOPOLOGY

SCENARIO

TWO DEVICES

WAN & CORE

1. PURPOSE OF WAN DEVICE

This is the end device, on which we have access. This device is connected to Vendor.

2. PURPOSE OF CORE DEVICE

This is the core layer device of datacenter, connecting to WAN device further

LOGS

WAN # sh cdp nei

Device ID Local Intrusion HoldTme Capability Platform Port ID

Fuse_core_1 Gig 2/1 155 RSI WS-C6513 Gig 13/41

PHYSICAL CONNECTION: WAN (Gig2 / 1) ========== CORE (Gig 13/41) 

WAN # sh ip ospf int g2 / 1 | i Process

Process ID 100,   router ID 10146192252, Network Type BROADCAST, Cost: 1

CORE # sh ip ospf int g13 / 41 | i Process

Process ID 65225,   router ID 10.146.1.254, Network Type BROADCAST, Cost: 1

CONCLUSION

On all the interfaces of WAN device, Process ID 100 is running on the CORE device, Process ID 65225 is running.

At WAN device, we have Process ID 100  & Area is 0, on interface connecting to CORE device  

At Core Device, we have Process ID 65225 & Area is 0, on interface connecting to WAN device   

QUERY

By default, Two process ID can not communicate with any other subnets.

How these two routers have different process, exchanging routes with each other?

What can be the design prospective in this scenario?

MORE LOGS FOR REFERNCE PURPOSE 

CORE # sh ip ospf int | i Process

Process ID 65225, Router ID 10.146.1.254, Network Type POINT_TO_POINT, Cost: 1

Process ID 65225, Router ID 10.146.1.254, Network Type BROADCAST, Cost: 1

CORE # sh ip ospf int | i Area

Internet Address 10.146.192.161/30, Area 0

Internet Address 10.146.192.133/30, Area 0

WAN # sh ip ospf int | i Process

Process ID 100, Router ID 10.146.192.252, Network Type LOOPBACK, Cost: 1

Process ID 100, Router ID 10.146.192.252, Network Type BROADCAST, Cost: 1

WAN # sh ip ospf int | i Area

Internet Address 10.146.192.252/32, Area 0

Internet Address 10.146.203.97/28, Area 0

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SOLUTION

Hey, re-think about statement

"Two different process ID can not communicate with each other"

That's true, above statement is correct, but there's a catch in the statement. So, i am re-phrasing the statement.

"Two different processes can not communicate with each other,

Or we can say

"Process ID is very significant to router"

Here, Two different processes are running, true, but on two different devices. So, this is a normal scenario. It will not create any problem. Routes will be exchanged between devices.