There are two tables you could look at to get the data:
- NPM_RoutingDefaultRouteChange - This will give you history of the changes for default route
- NPM_RoutingNeighbhor - this gives you Node, Neighhour IP and the LastChange date/time.
So if you want to just track the default route changes, then you have it in one table. If you want to know what the last change is for the routing neighbours, I suggest adding a trigger to log its history. If this is what you want, let me know and I can write one up.
I am also having issues with this could you assist?