The way I use NB: Is my network stable?
 

Somewhere in my network,
1) links are flapping,
2) routers are rebooting
3) somebody is making changes to EIGRP distribution list during the day
4) OSPF/EIGRP/BGP peering is resetting

How can I find out?

Step1: Create a Qmap including a few core routers which have most routes in your network. (gateway routers for your network management segment are good candidtates)

Step2: Run a routing benchmark from the map, and save the data into a folder called "snapshot1"

Step3: Wait for 30 seconds, and run another benchmark and save data into folder called "snapshot2"

Step4: Compare routing table between snapshot1 and snapshot2.

--> Click the routers with Add/Del/Modified route entries, and drag and drop each entry into a map.

Step 5: Enter the destination of problematic route into Search dialog to find out where the route is sourced from.

The source might be:
* Flapping link
* Rebooting routers
* Neighbor reset
* Distribution list modification in EIGRP


Note: You can examine and compare route tables for one router to achieve similar effects... in that case, you just need to launch routing table toolkit for that routers.

Re: The way I use NB: Is my network stable?
 

To discover unstable network elements, try sorting routing table by "age" field inside NetBrain. For the routes with age of seconds, drag-and-drop them to the map and trace to the source...

They are not stable.