From time to time I try to verify that all of my subnet boundaries are properly defined in AD Sites and Services. At some locations this is a little more challenging — especially when a site has many domain controllers. I recently threw together this PowerShell script to look at a site with over a dozen DCs:
Foreach ($server in get-content servers.txt) {Tail -10 \\$server\admin$\debug\netlogon.log | %{"$server,$_"}}
I had a file (servers.txt) that contained the name of each domain controller on a separate line. I ran the script using an Enterprise Admin account as it has permissions to the admin$ on each DC.
If you wanted to get really creative, you could add some select logic to get a list of all domain controllers. The get-date cmdlet could even compare the date format listed in the netlogon.log (MM-dd) and only give you the current days events. Throw in a scheduled task and now you could really be on top of this 🙂